'use strict'
/* eslint-disable */
//@flow

/** * * * * * * * * * *
 * Big Integer Library *
 * Created 2000        *
 * Leemon Baird        *
 * www.leemon.com      *
 * * * * * * * * * * * */

////////////////////////////////////////////////////////////////////////////////////////
// These functions are designed to avoid frequent dynamic memory allocation in the inner loop.
// For most functions, if it needs a BigInt as a local variable it will actually use
// a global, and will only allocate to it only when it's not the right size.  This ensures
// that when a function is called repeatedly with same-sized parameters, it only allocates
// memory on the first call.
//
// Note that for cryptographic purposes, the calls to Math.random() must
// be replaced with calls to a better pseudorandom number generator.
//
// In the following, "bigInt" means a bigInt with at least one leading zero element,
// and "integer" means a nonnegative integer less than radix.  In some cases, integer
// can be negative.  Negative bigInts are 2s complement.
//
// The following functions do not modify their inputs.
// Those returning a bigInt, string, or Array will dynamically allocate memory for that value.
// Those returning a boolean will return the integer 0 (false) or 1 (true).
// Those returning boolean or int will not allocate memory except possibly on the first
// time they're called with a given parameter size.
//
// bigInt  add(x,y)               //return (x+y) for bigInts x and y.
// bigInt  addInt(x,n)            //return (x+n) where x is a bigInt and n is an integer.
// string  bigInt2str(x,base)     //return a string form of bigInt x in a given base, with 2 <= base <= 95
// int     bitSize(x)             //return how many bits long the bigInt x is, not counting leading zeros
// bigInt  dup(x)                 //return a copy of bigInt x
// boolean equals(x,y)            //is the bigInt x equal to the bigint y?
// boolean equalsInt(x,y)         //is bigint x equal to integer y?
// bigInt  expand(x,n)            //return a copy of x with at least n elements, adding leading zeros if needed
// Array   findPrimes(n)          //return array of all primes less than integer n
// bigInt  GCD(x,y)               //return greatest common divisor of bigInts x and y (each with same number of elements).
// boolean greater(x,y)           //is x>y?  (x and y are nonnegative bigInts)
// boolean greaterShift(x,y,shift)//is (x <<(shift*bpe)) > y?
// bigInt  int2bigInt(t,n,m)      //return a bigInt equal to integer t, with at least n bits and m array elements
// bigInt  inverseMod(x,n)        //return (x**(-1) mod n) for bigInts x and n.  If no inverse exists, it returns null
// int     inverseModInt(x,n)     //return x**(-1) mod n, for integers x and n.  Return 0 if there is no inverse
// boolean isZero(x)              //is the bigInt x equal to zero?
// boolean millerRabin(x,b)       //does one round of Miller-Rabin base integer b say that bigInt x is possibly prime? (b is bigInt, 1<b<x)
// boolean millerRabinInt(x,b)    //does one round of Miller-Rabin base integer b say that bigInt x is possibly prime? (b is int,    1<b<x)
// bigInt  mod(x,n)               //return a new bigInt equal to (x mod n) for bigInts x and n.
// int     modInt(x,n)            //return x mod n for bigInt x and integer n.
// bigInt  mult(x,y)              //return x*y for bigInts x and y. This is faster when y<x.
// bigInt  multMod(x,y,n)         //return (x*y mod n) for bigInts x,y,n.  For greater speed, let y<x.
// boolean negative(x)            //is bigInt x negative?
// bigInt  powMod(x,y,n)          //return (x**y mod n) where x,y,n are bigInts and ** is exponentiation.  0**0=1. Faster for odd n.
// bigInt  randBigInt(n,s)        //return an n-bit random BigInt (n>=1).  If s=1, then the most significant of those n bits is set to 1.
// bigInt  randTruePrime(k)       //return a new, random, k-bit, true prime bigInt using Maurer's algorithm.
// bigInt  randProbPrime(k)       //return a new, random, k-bit, probable prime bigInt (probability it's composite less than 2^-80).
// bigInt  str2bigInt(s,b,n,m)    //return a bigInt for number represented in string s in base b with at least n bits and m array elements
// bigInt  sub(x,y)               //return (x-y) for bigInts x and y.  Negative answers will be 2s complement
// bigInt  trim(x,k)              //return a copy of x with exactly k leading zero elements
//
//
// The following functions each have a non-underscored version, which most users should call instead.
// These functions each write to a single parameter, and the caller is responsible for ensuring the array
// passed in is large enough to hold the result.
//
// void    addInt_(x,n)          //do x=x+n where x is a bigInt and n is an integer
// void    add_(x,y)             //do x=x+y for bigInts x and y
// void    copy_(x,y)            //do x=y on bigInts x and y
// void    copyInt_(x,n)         //do x=n on bigInt x and integer n
// void    GCD_(x,y)             //set x to the greatest common divisor of bigInts x and y, (y is destroyed).  (This never overflows its array).
// boolean inverseMod_(x,n)      //do x=x**(-1) mod n, for bigInts x and n. Returns 1 (0) if inverse does (doesn't) exist
// void    mod_(x,n)             //do x=x mod n for bigInts x and n. (This never overflows its array).
// void    mult_(x,y)            //do x=x*y for bigInts x and y.
// void    multMod_(x,y,n)       //do x=x*y  mod n for bigInts x,y,n.
// void    powMod_(x,y,n)        //do x=x**y mod n, where x,y,n are bigInts (n is odd) and ** is exponentiation.  0**0=1.
// void    randBigInt_(b,n,s)    //do b = an n-bit random BigInt. if s=1, then nth bit (most significant bit) is set to 1. n>=1.
// void    randTruePrime_(ans,k) //do ans = a random k-bit true random prime (not just probable prime) with 1 in the msb.
// void    sub_(x,y)             //do x=x-y for bigInts x and y. Negative answers will be 2s complement.
//
// The following functions do NOT have a non-underscored version.
// They each write a bigInt result to one or more parameters.  The caller is responsible for
// ensuring the arrays passed in are large enough to hold the results.
//
// void addShift_(x,y,ys)       //do x=x+(y<<(ys*bpe))
// void carry_(x)               //do carries and borrows so each element of the bigInt x fits in bpe bits.
// void divide_(x,y,q,r)        //divide x by y giving quotient q and remainder r
// int  divInt_(x,n)            //do x=floor(x/n) for bigInt x and integer n, and return the remainder. (This never overflows its array).
// void eGCD_(x,y,d,a,b)        //sets a,b,d to positive bigInts such that d = GCD_(x,y) = a*x-b*y
// void halve_(x)               //do x=floor(|x|/2)*sgn(x) for bigInt x in 2's complement.  (This never overflows its array).
// void leftShift_(x,n)         //left shift bigInt x by n bits.  n<bpe.
// void linComb_(x,y,a,b)       //do x=a*x+b*y for bigInts x and y and integers a and b
// void linCombShift_(x,y,b,ys) //do x=x+b*(y<<(ys*bpe)) for bigInts x and y, and integers b and ys
// void mont_(x,y,n,np)         //Montgomery multiplication (see comments where the function is defined)
// void multInt_(x,n)           //do x=x*n where x is a bigInt and n is an integer.
// void rightShift_(x,n)        //right shift bigInt x by n bits.  0 <= n < bpe. (This never overflows its array).
// void squareMod_(x,n)         //do x=x*x  mod n for bigInts x,n
// void subShift_(x,y,ys)       //do x=x-(y<<(ys*bpe)). Negative answers will be 2s complement.
//
// The following functions are based on algorithms from the _Handbook of Applied Cryptography_
//    powMod_()           = algorithm 14.94, Montgomery exponentiation
//    eGCD_,inverseMod_() = algorithm 14.61, Binary extended GCD_
//    GCD_()              = algorothm 14.57, Lehmer's algorithm
//    mont_()             = algorithm 14.36, Montgomery multiplication
//    divide_()           = algorithm 14.20  Multiple-precision division
//    squareMod_()        = algorithm 14.16  Multiple-precision squaring
//    randTruePrime_()    = algorithm  4.62, Maurer's algorithm
//    millerRabin()       = algorithm  4.24, Miller-Rabin algorithm
//
// Profiling shows:
//     randTruePrime_() spends:
//         10% of its time in calls to powMod_()
//         85% of its time in calls to millerRabin()
//     millerRabin() spends:
//         99% of its time in calls to powMod_()   (always with a base of 2)
//     powMod_() spends:
//         94% of its time in calls to mont_()  (almost always with x==y)
//
// This suggests there are several ways to speed up this library slightly:
//     - convert powMod_ to use a Montgomery form of k-ary window (or maybe a Montgomery form of sliding window)
//         -- this should especially focus on being fast when raising 2 to a power mod n
//     - convert randTruePrime_() to use a minimum r of 1/3 instead of 1/2 with the appropriate change to the test
//     - tune the parameters in randTruePrime_(), including c, m, and recLimit
//     - speed up the single loop in mont_() that takes 95% of the runtime, perhaps by reducing checking
//       within the loop when all the parameters are the same length.
//
// There are several ideas that look like they wouldn't help much at all:
//     - replacing trial division in randTruePrime_() with a sieve (that speeds up something taking almost no time anyway)
//     - increase bpe from 15 to 30 (that would help if we had a 32*32->64 multiplier, but not with JavaScript's 32*32->32)
//     - speeding up mont_(x,y,n,np) when x==y by doing a non-modular, non-Montgomery square
//       followed by a Montgomery reduction.  The intermediate answer will be twice as long as x, so that
//       method would be slower.  This is unfortunate because the code currently spends almost all of its time
//       doing mont_(x,x,...), both for randTruePrime_() and powMod_().  A faster method for Montgomery squaring
//       would have a large impact on the speed of randTruePrime_() and powMod_().  HAC has a couple of poorly-worded
//       sentences that seem to imply it's faster to do a non-modular square followed by a single
//       Montgomery reduction, but that's obviously wrong.
////////////////////////////////////////////////////////////////////////////////////////

export type Bool = 1 | 0

//globals
export var bpe = 0 //bits stored per array element
var mask = 0 //AND this with an array element to chop it down to bpe bits
var radix = mask + 1 //equals 2^bpe.  A single 1 bit to the left of the last bit of mask.

//the digits for converting to different bases
var digitsStr =
  '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_=!@#$%^&*()[]{}|;:,.<>/?`~ \\\'"+-'

//initialize the global variables

//bpe=number of bits in the mantissa on this platform
for (bpe = 0; 1 << (bpe + 1) > 1 << bpe; bpe++);
bpe >>= 1 //bpe=number of bits in one element of the array representing the bigInt
mask = (1 << bpe) - 1 //AND the mask with an integer to get its bpe least significant bits
radix = mask + 1 //2^bpe.  a single 1 bit to the left of the first bit of mask
export var one = int2bigInt(1, 1, 1) //constant used in powMod_()
export var zero = int2bigInt(0, 1, 1)

//the following global variables are scratchpad memory to
//reduce dynamic memory allocation in the inner loop
var t: number[] | number = new Array(0)
var ss = t //used in mult_()
var s0 = t //used in multMod_(), squareMod_()
// var s1=t;    //used in powMod_(), multMod_(), squareMod_()
// var s2=t;    //used in powMod_(), multMod_()
var s3 = t //used in powMod_()
var s4 = t,
    s5 = t //used in mod_()
var s6 = t //used in bigInt2str()
var s7 = t //used in powMod_()
var T = t //used in GCD_()
var sa = t //used in mont_()
var mr_x1 = t,
    mr_r = t,
    mr_a = t, //used in millerRabin()
    eg_v = t,
    eg_u = t,
    eg_A = t,
    eg_B = t,
    eg_C = t,
    eg_D = t, //used in eGCD_(), inverseMod_()
    //, md_q1=t, md_q2=t, md_q3=t, md_r=t, md_r1=t, md_r2=t, md_tt=t, //used in mod_()

    primes = t,
    pows = t,
    s_i = t,
    s_i2 = t,
    s_R = t,
    s_rm = t,
    s_q = t,
    s_n1 = t,
    s_a = t,
    s_r2 = t,
    s_n = t,
    s_b = t,
    s_d = t,
    s_x1 = t,
    s_x2 = t,
    s_aa = t, //used in randTruePrime_()
    rpprb = t //used in randProbPrimeRounds() (which also uses "primes")

////////////////////////////////////////////////////////////////////////////////////////

var k, buff

/**
 * return array of all primes less than integer n
 *
 * @param {number} n
 * @returns {number[]}
 */
export function findPrimes(n: number): number[] {
  var i, s, p, ans
  s = new Array(n)
  for (i = 0; i < n; i++) s[i] = 0
  s[0] = 2
  p = 0 //first p elements of s are primes, the rest are a sieve
  for (; s[p] < n; ) {
    //s[p] is the pth prime
    for (
      i = s[p] * s[p];
      i < n;
      i += s[p] //mark multiples of s[p]
    )
      s[i] = 1
    p++
    s[p] = s[p - 1] + 1
    for (; s[p] < n && s[s[p]]; s[p]++); //find next prime (where s[p]==0)
  }
  ans = new Array(p)
  for (i = 0; i < p; i++) ans[i] = s[i]
  return ans
}

/**
 * does a single round of Miller-Rabin base b consider x to be a possible prime?
 *
 * x is a bigInt, and b is an integer, with b<x
 *
 * @export
 * @param {number[]} x
 * @param {number} b
 * @returns {(0 | 1)}
 */
export function millerRabinInt(x: number[], b: number): Bool {
  if (mr_x1.length !== x.length) {
    mr_x1 = dup(x)
    mr_r = dup(x)
    mr_a = dup(x)
  }

  copyInt_(mr_a, b)
  return millerRabin(x, mr_a)
}

/**
 * does a single round of Miller-Rabin base b consider x to be a possible prime?
 *
 * x and b are bigInts with b<x
 *
 * @export
 * @param {number[]} x
 * @param {number[]} b
 * @returns {(0 | 1)}
 */
export function millerRabin(x: number[], b: number[]): Bool {
  var i, j, k, s

  if (mr_x1.length !== x.length) {
    mr_x1 = dup(x)
    mr_r = dup(x)
    mr_a = dup(x)
  }

  copy_(mr_a, b)
  copy_(mr_r, x)
  copy_(mr_x1, x)

  addInt_(mr_r, -1)
  addInt_(mr_x1, -1)

  //s=the highest power of two that divides mr_r
  k = 0
  for (i = 0; i < mr_r.length; i++)
    for (j = 1; j < mask; j <<= 1)
      if (x[i] & j) {
        s = k < mr_r.length + bpe ? k : 0
        i = mr_r.length
        j = mask
      } else k++

  if (s) rightShift_(mr_r, s)

  powMod_(mr_a, mr_r, x)

  if (!equalsInt(mr_a, 1) && !equals(mr_a, mr_x1)) {
    j = 1
    //$off
    while (j <= s - 1 && !equals(mr_a, mr_x1)) {
      squareMod_(mr_a, x)
      if (equalsInt(mr_a, 1)) {
        return 0
      }
      j++
    }
    if (!equals(mr_a, mr_x1)) {
      return 0
    }
  }
  return 1
}

/**
 * returns how many bits long the bigInt is, not counting leading zeros.
 *
 * @param {number[]} x
 * @returns {number}
 */
export function bitSize(x: number[]): number {
  var j, z, w
  for (j = x.length - 1; x[j] == 0 && j > 0; j--);
  for (z = 0, w = x[j]; w; w >>= 1, z++);
  z += bpe * j
  return z
}

/**
 * return a copy of x with at least n elements, adding leading zeros if needed
 *
 * @param {number[]} x
 * @param {number} n
 * @returns {number[]}
 */
export function expand(x: number[], n: number): number[] {
  var ans = int2bigInt(0, (x.length > n ? x.length : n) * bpe, 0)
  copy_(ans, x)
  return ans
}

/**
 * return a k-bit true random prime using Maurer's algorithm.
 *
 * @export
 * @param {number} k
 * @returns {number[]}
 */
/* export function randTruePrime(k: number): number[] {
  var ans = int2bigInt(0, k, 0)
  randTruePrime_(ans, k)
  return trim(ans, 1)
} */

/**
 * return a k-bit random probable prime with probability of error < 2^-80
 *
 * @export
 * @param {number} k
 * @returns {number[]}
 */
/* export function randProbPrime(k: number): number[] {
  if (k >= 600) return randProbPrimeRounds(k, 2) //numbers from HAC table 4.3
  if (k >= 550) return randProbPrimeRounds(k, 4)
  if (k >= 500) return randProbPrimeRounds(k, 5)
  if (k >= 400) return randProbPrimeRounds(k, 6)
  if (k >= 350) return randProbPrimeRounds(k, 7)
  if (k >= 300) return randProbPrimeRounds(k, 9)
  if (k >= 250) return randProbPrimeRounds(k, 12) //numbers from HAC table 4.4
  if (k >= 200) return randProbPrimeRounds(k, 15)
  if (k >= 150) return randProbPrimeRounds(k, 18)
  if (k >= 100) return randProbPrimeRounds(k, 27)
  return randProbPrimeRounds(k, 40) //number from HAC remark 4.26 (only an estimate)
} */

/**
 * return a k-bit probable random prime using n rounds of Miller Rabin
 * (after trial division with small primes)
 *
 * @export
 * @param {number} k
 * @param {number} n
 * @returns {number[]}
 */
/* export function randProbPrimeRounds(k: number, n: number): number[] {
  var ans, i, divisible, B
  B = 30000 //B is largest prime to use in trial division
  ans = int2bigInt(0, k, 0)

  //optimization: try larger and smaller B to find the best limit.

  if (primes.length === 0) primes = findPrimes(30000) //check for divisibility by primes <=30000

  if (rpprb.length !== ans.length) rpprb = dup(ans)

  for (;;) {
    //keep trying random values for ans until one appears to be prime
    //optimization: pick a random number times L=2*3*5*...*p, plus a
    //   random element of the list of all numbers in [0,L) not divisible by any prime up to p.
    //   This can reduce the amount of random number generation.

    randBigInt_(ans, k, 0) //ans = a random odd number to check
    ans[0] |= 1
    divisible = 0

    //check ans for divisibility by small primes up to B
    for (i = 0; i < primes.length && primes[i] <= B; i++)
      if (modInt(ans, primes[i]) === 0 && !equalsInt(ans, primes[i])) {
        divisible = 1
        break
      }

    //optimization: change millerRabin so the base can be bigger than the number being checked, then eliminate the while here.

    //do n rounds of Miller Rabin, with random bases less than ans
    for (i = 0; i < n && !divisible; i++) {
      randBigInt_(rpprb, k, 0)
      while (
        !greater(ans, rpprb) //pick a random rpprb that's < ans
      )
        randBigInt_(rpprb, k, 0)
      if (!millerRabin(ans, rpprb)) divisible = 1
    }

    if (!divisible) return ans
  }
} */

/**
 * return a new bigInt equal to (x mod n) for bigInts x and n.
 *
 * @param {number[]} x
 * @param {number[]} n
 * @returns {number[]}
 */
export function mod(x: number[], n: number[]): number[] {
  var ans = dup(x)
  mod_(ans, n)
  return trim(ans, 1)
}

/**
 * return (x+n) where x is a bigInt and n is an integer.
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 * @returns {number[]}
 */
/* export function addInt(x: number[], n: number): number[] {
  var ans = expand(x, x.length + 1)
  addInt_(ans, n)
  return trim(ans, 1)
} */

/**
 * return x*y for bigInts x and y. This is faster when y<x.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {number[]}
 */
export function mult(x: number[], y: number[]): number[] {
  var ans = expand(x, x.length + y.length)
  mult_(ans, y)
  return trim(ans, 1)
}

/**
 * return (x**y mod n) where x,y,n are bigInts and ** is exponentiation.
 *
 * 0**0=1.
 *
 * Faster for odd n.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} n
 * @returns {number[]}
 */
export function powMod(x: number[], y: number[], n: number[]): number[] {
  var ans = expand(x, n.length)
  powMod_(
    //this should work without the trim, but doesn't
    ans,
    trim(y, 2),
    trim(n, 2),
  )
  return trim(ans, 1)
}

/**
 * Simple pow with no optimizations (in 40x times slower than jsbn's pow)
 * @param x bigInt
 * @param e
 */
export function pow(x: number[], e: number) {
  let ans = dup(x);
  e -= 1;
  for(let i = 0; i < e; ++i) {
    ans = mult(ans, x);
  }
  return trim(ans, 1);
}

/**
 * return (x-y) for bigInts x and y
 *
 * Negative answers will be 2s complement
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {number[]}
 */
export function sub(x: number[], y: number[]): number[] {
  var ans = expand(x, x.length > y.length ? x.length + 1 : y.length + 1)
  sub_(ans, y)
  return trim(ans, 1)
}

/**
 * return (x+y) for bigInts x and y
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {number[]}
 */
export function add(x: number[], y: number[]): number[] {
  var ans = expand(x, x.length > y.length ? x.length + 1 : y.length + 1)
  add_(ans, y)
  return trim(ans, 1)
}

/**
 * return (x**(-1) mod n) for bigInts x and n.
 *
 * If no inverse exists, it returns null
 *
 * @param {number[]} x
 * @param {number[]} n
 * @returns {(number[] | null)}
 */
/* export function inverseMod(x: number[], n: number[]): number[] | null {
  var ans = expand(x, n.length)
  var s = inverseMod_(ans, n)
  return s ? trim(ans, 1) : null
} */

/**
 * return (x*y mod n) for bigInts x,y,n.
 *
 * For greater speed, let y<x.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} n
 * @returns {number[]}
 */
export function multMod(x: number[], y: number[], n: number[]): number[] {
  var ans = expand(x, n.length)
  multMod_(ans, y, n)
  return trim(ans, 1)
}

/**
 * generate a k-bit true random prime using Maurer's algorithm, and put it into ans.
 *
 * The bigInt ans must be large enough to hold it.
 *
 * @export
 * @param {number[]} ans
 * @param {number} k
 * @return {void}
 */
/* export function randTruePrime_(ans: number[], k: number): void {
  var c, m, pm, dd, j, r, B, divisible, z, zz, recSize
  var w
  if (primes.length == 0) primes = findPrimes(30000) //check for divisibility by primes <=30000

  if (pows.length == 0) {
    pows = new Array(512)
    for (j = 0; j < 512; j++) {
      pows[j] = Math.pow(2, j / 511 - 1)
    }
  }

  //c and m should be tuned for a particular machine and value of k, to maximize speed
  c = 0.1 //c=0.1 in HAC
  m = 20 //generate this k-bit number by first recursively generating a number that has between k/2 and k-m bits
  var recLimit = 20 //stop recursion when k <=recLimit.  Must have recLimit >= 2

  if (s_i2.length != ans.length) {
    s_i2 = dup(ans)
    s_R = dup(ans)
    s_n1 = dup(ans)
    s_r2 = dup(ans)
    s_d = dup(ans)
    s_x1 = dup(ans) //TODO Seems like a bug in eslint, reports as unused
    s_x2 = dup(ans)
    s_b = dup(ans)
    s_n = dup(ans)
    s_i = dup(ans)
    s_rm = dup(ans)
    s_q = dup(ans)
    s_a = dup(ans)
    s_aa = dup(ans)
  }

  if (k <= recLimit) {
    //generate small random primes by trial division up to its square root
    pm = (1 << ((k + 2) >> 1)) - 1 //pm is binary number with all ones, just over sqrt(2^k)
    copyInt_(ans, 0)
    for (dd = 1; dd; ) {
      dd = 0
      ans[0] = 1 | (1 << (k - 1)) | Math.floor(Math.random() * (1 << k)) //random, k-bit, odd integer, with msb 1
      for (j = 1; j < primes.length && (primes[j] & pm) == primes[j]; j++) {
        //trial division by all primes 3...sqrt(2^k)
        if (0 == ans[0] % primes[j]) {
          dd = 1
          break
        }
      }
    }
    carry_(ans)
    return
  }

  B = c * k * k //try small primes up to B (or all the primes[] array if the largest is less than B).
  if (k > 2 * m)
    //generate this k-bit number by first recursively generating a number that has between k/2 and k-m bits
    for (r = 1; k - k * r <= m; ) r = pows[Math.floor(Math.random() * 512)] //r=Math.pow(2,Math.random()-1);
  else r = 0.5

  //simulation suggests the more complex algorithm using r=.333 is only slightly faster.

  recSize = Math.floor(r * k) + 1

  randTruePrime_(s_q, recSize)
  copyInt_(s_i2, 0)
  s_i2[Math.floor((k - 2) / bpe)] |= 1 << ((k - 2) % bpe) //s_i2=2^(k-2)
  divide_(s_i2, s_q, s_i, s_rm) //s_i=floor((2^(k-1))/(2q))

  z = bitSize(s_i)

  for (;;) {
    for (;;) {
      //generate z-bit numbers until one falls in the range [0,s_i-1]
      randBigInt_(s_R, z, 0)
      if (greater(s_i, s_R)) break
    } //now s_R is in the range [0,s_i-1]
    addInt_(s_R, 1) //now s_R is in the range [1,s_i]
    add_(s_R, s_i) //now s_R is in the range [s_i+1,2*s_i]

    copy_(s_n, s_q)
    mult_(s_n, s_R)
    multInt_(s_n, 2)
    addInt_(s_n, 1) //s_n=2*s_R*s_q+1

    copy_(s_r2, s_R)
    multInt_(s_r2, 2) //s_r2=2*s_R

    //check s_n for divisibility by small primes up to B
    for (divisible = 0, j = 0; j < primes.length && primes[j] < B; j++)
      if (modInt(s_n, primes[j]) == 0 && !equalsInt(s_n, primes[j])) {
        divisible = 1
        break
      }

    if (!divisible)
      if (!millerRabinInt(s_n, 2))
        //if it passes small primes check, then try a single Miller-Rabin base 2
        //this line represents 75% of the total runtime for randTruePrime_
        divisible = 1

    if (!divisible) {
      //if it passes that test, continue checking s_n
      addInt_(s_n, -3)
      for (j = s_n.length - 1; s_n[j] == 0 && j > 0; j--); //strip leading zeros
      for (zz = 0, w = s_n[j]; w; w >>= 1, zz++);
      zz += bpe * j //zz=number of bits in s_n, ignoring leading zeros
      for (;;) {
        //generate z-bit numbers until one falls in the range [0,s_n-1]
        randBigInt_(s_a, zz, 0)
        if (greater(s_n, s_a)) break
      } //now s_a is in the range [0,s_n-1]
      addInt_(s_n, 3) //now s_a is in the range [0,s_n-4]
      addInt_(s_a, 2) //now s_a is in the range [2,s_n-2]
      copy_(s_b, s_a)
      copy_(s_n1, s_n)
      addInt_(s_n1, -1)
      powMod_(s_b, s_n1, s_n) //s_b=s_a^(s_n-1) modulo s_n
      addInt_(s_b, -1)
      if (isZero(s_b)) {
        copy_(s_b, s_a)
        powMod_(s_b, s_r2, s_n)
        addInt_(s_b, -1)
        copy_(s_aa, s_n)
        copy_(s_d, s_b)
        GCD_(s_d, s_n) //if s_b and s_n are relatively prime, then s_n is a prime
        if (equalsInt(s_d, 1)) {
          copy_(ans, s_aa)
          return //if we've made it this far, then s_n is absolutely guaranteed to be prime
        }
      }
    }
  }
} */

/**
 * Return an n-bit random BigInt (n>=1).  If s=1, then the most significant of those n bits is set to 1.
 *
 * @export
 * @param {number} n
 * @param {number} s
 * @returns {number[]}
 */
/* export function randBigInt(n: number, s: number): number[] {
  var a, b
  a = Math.floor((n - 1) / bpe) + 2 //# array elements to hold the BigInt with a leading 0 element
  b = int2bigInt(0, 0, a)
  randBigInt_(b, n, s)
  return b
} */

/**
 * Set b to an n-bit random BigInt.  If s=1, then the most significant of those n bits is set to 1.
 *
 * Array b must be big enough to hold the result. Must have n>=1
 *
 * @export
 * @param {number[]} b
 * @param {number} n
 * @param {number} s
 * @return {void}
 */
/* export function randBigInt_(b: number[], n: number, s: number): void {
  var i, a
  for (i = 0; i < b.length; i++) b[i] = 0
  a = Math.floor((n - 1) / bpe) + 1 //# array elements to hold the BigInt
  for (i = 0; i < a; i++) {
    b[i] = Math.floor(Math.random() * (1 << (bpe - 1)))
  }
  b[a - 1] &= (2 << ((n - 1) % bpe)) - 1
  if (s == 1) b[a - 1] |= 1 << ((n - 1) % bpe)
} */

/**
 * Return the greatest common divisor of bigInts x and y (each with same number of elements).
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {number[]}
 */
export function GCD(x: number[], y: number[]): number[] {
  var xc, yc
  xc = dup(x)
  yc = dup(y)
  GCD_(xc, yc)
  return xc
}

/**
 * set x to the greatest common divisor of bigInts x and y (each with same number of elements).
 *
 * y is destroyed.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 */
export function GCD_(x: number[], y: number[]): void {
  var i: number, xp: number, yp: number, A: number, B, C: number, D: number, q, sing
  var qp
  if (T.length !== x.length) T = dup(x)

  sing = 1
  while (sing) {
    //while y has nonzero elements other than y[0]
    sing = 0
    for (
      i = 1;
      i < y.length;
      i++ //check if y has nonzero elements other than 0
    )
      if (y[i]) {
        sing = 1
        break
      }
    if (!sing) break //quit when y all zero elements except possibly y[0]

    for (i = x.length; !x[i] && i >= 0; i--); //find most significant element of x
    xp = x[i]
    yp = y[i]
    A = 1
    B = 0
    C = 0
    D = 1
    while (yp + C && yp + D) {
      q = Math.floor((xp + A) / (yp + C))
      qp = Math.floor((xp + B) / (yp + D))
      if (q != qp) break
      t = A - q * C
      A = C
      C = t //  do (A,B,xp, C,D,yp) = (C,D,yp, A,B,xp) - q*(0,0,0, C,D,yp)
      t = B - q * D
      B = D
      D = t
      t = xp - q * yp
      xp = yp
      yp = t
    }
    if (B) {
      copy_(T, x)
      linComb_(x, y, A, B) //x=A*x+B*y
      linComb_(y, T, D, C) //y=D*y+C*T
    } else {
      mod_(x, y)
      copy_(T, x)
      copy_(x, y)
      copy_(y, T)
    }
  }
  if (y[0] === 0) return
  t = modInt(x, y[0])
  copyInt_(x, y[0])
  y[0] = t
  while (y[0]) {
    x[0] %= y[0]
    t = x[0]
    x[0] = y[0]
    y[0] = t
  }
}

/**
 * do x=x**(-1) mod n, for bigInts x and n.
 *
 * If no inverse exists, it sets x to zero and returns 0, else it returns 1.
 * The x array must be at least as large as the n array.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} n
 * @returns {(0 | 1)}
 */
/* export function inverseMod_(x: number[], n: number[]): Bool {
  var k = 1 + 2 * Math.max(x.length, n.length)

  if (!(x[0] & 1) && !(n[0] & 1)) {
    //if both inputs are even, then inverse doesn't exist
    copyInt_(x, 0)
    return 0
  }

  if (eg_u.length != k) {
    eg_u = new Array(k)
    eg_v = new Array(k)
    eg_A = new Array(k)
    eg_B = new Array(k)
    eg_C = new Array(k)
    eg_D = new Array(k)
  }

  copy_(eg_u, x)
  copy_(eg_v, n)
  copyInt_(eg_A, 1)
  copyInt_(eg_B, 0)
  copyInt_(eg_C, 0)
  copyInt_(eg_D, 1)
  for (;;) {
    while (!(eg_u[0] & 1)) {
      //while eg_u is even
      halve_(eg_u)
      if (!(eg_A[0] & 1) && !(eg_B[0] & 1)) {
        //if eg_A==eg_B==0 mod 2
        halve_(eg_A)
        halve_(eg_B)
      } else {
        add_(eg_A, n)
        halve_(eg_A)
        sub_(eg_B, x)
        halve_(eg_B)
      }
    }

    while (!(eg_v[0] & 1)) {
      //while eg_v is even
      halve_(eg_v)
      if (!(eg_C[0] & 1) && !(eg_D[0] & 1)) {
        //if eg_C==eg_D==0 mod 2
        halve_(eg_C)
        halve_(eg_D)
      } else {
        add_(eg_C, n)
        halve_(eg_C)
        sub_(eg_D, x)
        halve_(eg_D)
      }
    }

    if (!greater(eg_v, eg_u)) {
      //eg_v <= eg_u
      sub_(eg_u, eg_v)
      sub_(eg_A, eg_C)
      sub_(eg_B, eg_D)
    } else {
      //eg_v > eg_u
      sub_(eg_v, eg_u)
      sub_(eg_C, eg_A)
      sub_(eg_D, eg_B)
    }

    if (equalsInt(eg_u, 0)) {
      while (
        negative(eg_C) //make sure answer is nonnegative
      )
        add_(eg_C, n)
      copy_(x, eg_C)

      if (!equalsInt(eg_v, 1)) {
        //if GCD_(x,n)!=1, then there is no inverse
        copyInt_(x, 0)
        return 0
      }
      return 1
    }
  }
} */

/**
 * return x**(-1) mod n, for integers x and n.
 *
 * Return 0 if there is no inverse
 *
 * @param {number} x
 * @param {number} n
 * @returns {number}
 */
export function inverseModInt(x: number, n: number): number {
  var a = 1,
      b = 0,
      t
  for (;;) {
    if (x === 1) return a
    if (x === 0) return 0
    b -= a * Math.floor(n / x)
    //$off
    n %= x

    if (n === 1) return b //to avoid negatives, change this b to n-b, and each -= to +=
    if (n === 0) return 0
    a -= b * Math.floor(x / n)
    //$off
    x %= n
  }
  /*::
  declare var never: empty
  return never
  */
}

//this deprecated function is for backward compatibility only.
/* function inverseModInt_(x: number, n: number) {
  return inverseModInt(x, n)
} */

/**
 * Given positive bigInts x and y, change the bigints v, a, and b to positive bigInts such that:
 *
 *      v = GCD_(x,y) = a*x-b*y
 *
 * The bigInts v, a, b, must have exactly as many elements as the larger of x and y.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} v
 * @param {number[]} a
 * @param {number[]} b
 * @return {void}
 */
export function eGCD_(
  x: number[],
  y: number[],
  v: number[],
  a: number[],
  b: number[],
): void {
  var g = 0
  var k = Math.max(x.length, y.length)
  if (eg_u.length != k) {
    eg_u = new Array(k)
    eg_A = new Array(k)
    eg_B = new Array(k)
    eg_C = new Array(k)
    eg_D = new Array(k)
  }
  while (!(x[0] & 1) && !(y[0] & 1)) {
    //while x and y both even
    halve_(x)
    halve_(y)
    g++
  }
  copy_(eg_u, x)
  copy_(v, y)
  copyInt_(eg_A, 1)
  copyInt_(eg_B, 0)
  copyInt_(eg_C, 0)
  copyInt_(eg_D, 1)
  for (;;) {
    while (!(eg_u[0] & 1)) {
      //while u is even
      halve_(eg_u)
      if (!(eg_A[0] & 1) && !(eg_B[0] & 1)) {
        //if A==B==0 mod 2
        halve_(eg_A)
        halve_(eg_B)
      } else {
        add_(eg_A, y)
        halve_(eg_A)
        sub_(eg_B, x)
        halve_(eg_B)
      }
    }

    while (!(v[0] & 1)) {
      //while v is even
      halve_(v)
      if (!(eg_C[0] & 1) && !(eg_D[0] & 1)) {
        //if C==D==0 mod 2
        halve_(eg_C)
        halve_(eg_D)
      } else {
        add_(eg_C, y)
        halve_(eg_C)
        sub_(eg_D, x)
        halve_(eg_D)
      }
    }

    if (!greater(v, eg_u)) {
      //v<=u
      sub_(eg_u, v)
      sub_(eg_A, eg_C)
      sub_(eg_B, eg_D)
    } else {
      //v>u
      sub_(v, eg_u)
      sub_(eg_C, eg_A)
      sub_(eg_D, eg_B)
    }
    if (equalsInt(eg_u, 0)) {
      while (negative(eg_C)) {
        //make sure a (C) is nonnegative
        add_(eg_C, y)
        sub_(eg_D, x)
      }
      multInt_(eg_D, -1) ///make sure b (D) is nonnegative
      copy_(a, eg_C)
      copy_(b, eg_D)
      leftShift_(v, g)
      return
    }
  }
}

/**
 * is bigInt x negative?
 *
 * @param {number[]} x
 * @returns {(1 | 0)}
 */
export function negative(x: number[]) {
  //TODO Flow Bool type inference
  return (x[x.length - 1] >> (bpe - 1)) & 1
}

/**
 * is (x << (shift*bpe)) > y?
 *
 * x and y are nonnegative bigInts
 * shift is a nonnegative integer
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number} shift
 * @returns {(1 | 0)}
 */
export function greaterShift(x: number[], y: number[], shift: number): Bool {
  var i,
      kx = x.length,
      ky = y.length
  k = kx + shift < ky ? kx + shift : ky
  for (i = ky - 1 - shift; i < kx && i >= 0; i++) if (x[i] > 0) return 1 //if there are nonzeros in x to the left of the first column of y, then x is bigger
  for (i = kx - 1 + shift; i < ky; i++) if (y[i] > 0) return 0 //if there are nonzeros in y to the left of the first column of x, then x is not bigger
  for (i = k - 1; i >= shift; i--)
    if (x[i - shift] > y[i]) return 1
    else if (x[i - shift] < y[i]) return 0
  return 0
}

/**
 * is x > y?
 *
 * x and y both nonnegative
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {(1 | 0)}
 */
export function greater(x: number[], y: number[]): Bool {
  var i
  var k = x.length < y.length ? x.length : y.length

  for (i = x.length; i < y.length; i++) if (y[i]) return 0 //y has more digits

  for (i = y.length; i < x.length; i++) if (x[i]) return 1 //x has more digits

  for (i = k - 1; i >= 0; i--)
    if (x[i] > y[i]) return 1
    else if (x[i] < y[i]) return 0
  return 0
}

/**
 * divide x by y giving quotient q and remainder r.
 *
 *     q = floor(x/y)
 *     r = x mod y
 *
 * All 4 are bigints.
 *
 * * x must have at least one leading zero element.
 * * y must be nonzero.
 * * q and r must be arrays that are exactly the same length as x. (Or q can have more).
 * * Must have x.length >= y.length >= 2.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} q
 * @param {number[]} r
 * @return {void}
 */
export function divide_(
  x: number[],
  y: number[],
  q: number[],
  r: number[],
): void {
  var kx, ky
  var i, j, y1, y2, c, a, b
  copy_(r, x)
  for (ky = y.length; y[ky - 1] === 0; ky--); //ky is number of elements in y, not including leading zeros

  //normalize: ensure the most significant element of y has its highest bit set
  b = y[ky - 1]
  for (a = 0; b; a++) b >>= 1
  a = bpe - a //a is how many bits to shift so that the high order bit of y is leftmost in its array element
  leftShift_(y, a) //multiply both by 1<<a now, then divide both by that at the end
  leftShift_(r, a)

  //Rob Visser discovered a bug: the following line was originally just before the normalization.
  for (kx = r.length; r[kx - 1] === 0 && kx > ky; kx--); //kx is number of elements in normalized x, not including leading zeros

  copyInt_(q, 0) // q=0
  while (!greaterShift(y, r, kx - ky)) {
    // while (leftShift_(y,kx-ky) <= r) {
    subShift_(r, y, kx - ky) //   r=r-leftShift_(y,kx-ky)
    q[kx - ky]++ //   q[kx-ky]++;
  } // }

  for (i = kx - 1; i >= ky; i--) {
    if (r[i] == y[ky - 1]) q[i - ky] = mask
    else q[i - ky] = Math.floor((r[i] * radix + r[i - 1]) / y[ky - 1])

    //The following for(;;) loop is equivalent to the commented while loop,
    //except that the uncommented version avoids overflow.
    //The commented loop comes from HAC, which assumes r[-1]==y[-1]==0
    //  while (q[i-ky]*(y[ky-1]*radix+y[ky-2]) > r[i]*radix*radix+r[i-1]*radix+r[i-2])
    //    q[i-ky]--;
    for (;;) {
      y2 = (ky > 1 ? y[ky - 2] : 0) * q[i - ky]
      c = y2 >> bpe
      y2 = y2 & mask
      y1 = c + q[i - ky] * y[ky - 1]
      c = y1 >> bpe
      y1 = y1 & mask

      if (
        c == r[i]
          ? y1 == r[i - 1] ? y2 > (i > 1 ? r[i - 2] : 0) : y1 > r[i - 1]
          : c > r[i]
      )
        q[i - ky]--
      else break
    }

    linCombShift_(r, y, -q[i - ky], i - ky) //r=r-q[i-ky]*leftShift_(y,i-ky)
    if (negative(r)) {
      addShift_(r, y, i - ky) //r=r+leftShift_(y,i-ky)
      q[i - ky]--
    }
  }

  rightShift_(y, a) //undo the normalization step
  rightShift_(r, a) //undo the normalization step
}

/**
 * do carries and borrows so each element of the bigInt x fits in bpe bits.
 *
 * @param {number[]} x
 */
export function carry_(x: number[]): void {
  var i, k, c, b
  k = x.length
  c = 0
  for (i = 0; i < k; i++) {
    c += x[i]
    b = 0
    if (c < 0) {
      b = -(c >> bpe)
      c += b * radix
    }
    x[i] = c & mask
    c = (c >> bpe) - b
  }
}

/**
 * return x mod n for bigInt x and integer n.
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 * @returns {number}
 */
export function modInt(x: number[], n: number): number {
  var i,
      c = 0
  for (i = x.length - 1; i >= 0; i--) c = (c * radix + x[i]) % n
  return c
}

/**
 * convert the integer t into a bigInt with at least the given number of bits.
 * the returned array stores the bigInt in bpe-bit chunks, little endian (buff[0] is least significant word)
 * Pad the array with leading zeros so that it has at least minSize elements.
 *
 * There will always be at least one leading 0 element.
 *
 * @export
 * @param {number} t
 * @param {number} bits
 * @param {number} minSize
 * @returns {number[]}
 */
export function int2bigInt(t: number, bits: number, minSize: number): number[] {
  var i, k
  k = Math.ceil(bits / bpe) + 1
  k = minSize > k ? minSize : k
  var buff = new Array(k)
  copyInt_(buff, t)
  return buff
}

/**
 * return the bigInt given a string representation in a given base.
 * Pad the array with leading zeros so that it has at least minSize elements.
 * If base=-1, then it reads in a space-separated list of array elements in decimal.
 *
 * The array will always have at least one leading zero, unless base=-1.
 *
 * @export
 * @param {string} s
 * @param {number} base
 * @param {number} [minSize]
 * @returns {number[]}
 */
export function str2bigInt(
  s: string,
  base: number,
  minSize?: number,
): number[] {
  var d, i, x, y, kk
  var k = s.length
  if (base === -1) {
    //comma-separated list of array elements in decimal
    x = new Array(0)
    for (;;) {
      y = new Array(x.length + 1)
      for (i = 0; i < x.length; i++) y[i + 1] = x[i]
      y[0] = parseInt(s, 10) //TODO PERF Should we replace that with ~~ (not not)? https://jsperf.com/number-vs-parseint-vs-plus/7
      x = y
      d = s.indexOf(',', 0)
      if (d < 1) break
      //$off
      s = s.substring(d + 1)
      if (s.length == 0) break
    }
    //$off
    if (x.length < minSize) {
      //$off
      y = new Array(minSize)
      copy_(y, x)
      return y
    }
    return x
  }

  x = int2bigInt(0, base * k, 0)
  for (i = 0; i < k; i++) {
    d = digitsStr.indexOf(s.substring(i, i + 1), 0)
    if (base <= 36 && d >= 36)
      //convert lowercase to uppercase if base<=36
      d -= 26
    if (d >= base || d < 0) {
      //stop at first illegal character
      break
    }
    multInt_(x, base)
    addInt_(x, d)
  }

  for (k = x.length; k > 0 && !x[k - 1]; k--); //strip off leading zeros
  //$off
  k = minSize > k + 1 ? minSize : k + 1
  //$off
  y = new Array(k)
  //$off
  kk = k < x.length ? k : x.length
  //$off
  for (i = 0; i < kk; i++) y[i] = x[i]
  //$off
  for (; i < k; i++) y[i] = 0
  return y
}

//return the bigInt given a string representation in a given base.
//Pad the array with leading zeros so that it has at least minSize elements.
//If base=-1, then it reads in a space-separated list of array elements in decimal.
//The array will always have at least one leading zero, unless base=-1.
// function str2bigInt(s,b,minSize) {
//   var d, i, j, base, str, x, y, kk;
//   if (typeof b === 'string') {
//           base = b.length;
//           str = b;
//   } else {
//           base = b;
//           str = digitsStr;
//   }
//   var k=s.length;
//   if (base==-1) { //comma-separated list of array elements in decimal
//       x=new Array(0);
//       for (;;) {
//           y=new Array(x.length+1);
//           for (i=0;i<x.length;i++)
//               y[i+1]=x[i];
//           y[0]=parseInt(s,10);
//           x=y;
//           d=s.indexOf(',',0);
//           if (d<1)
//               break;
//           s=s.substring(d+1);
//           if (s.length==0)
//               break;
//       }
//       if (x.length<minSize) {
//           y=new Array(minSize);
//           copy_(y,x);
//           return y;
//       }
//       return x;
//   }

//   x=int2bigInt(0,base*k,0);
// for (i=0;i<k;i++) {
//   d=str.indexOf(s.substring(i,i+1),0);
//   if (base<=36 && d>=36) { //convert lowercase to uppercase if base<=36
//       d-=26;
//   }
//   if (d>=base || d<0) {   //ignore illegal characters
//   continue;
//       }
//       multInt_(x,base);
//       addInt_(x,d);
//   }

//   for (k=x.length;k>0 && !x[k-1];k--); //strip off leading zeros
//   k=minSize>k+1 ? minSize : k+1;
//   y=new Array(k);
//   kk=k<x.length ? k : x.length;
//   for (i=0;i<kk;i++)
//       y[i]=x[i];
//   for (;i<k;i++)
//       y[i]=0;
//   return y;
// }

/**
 * is bigint x equal to integer y?
 *
 * y must have less than bpe bits
 *
 * @export
 * @param {number[]} x
 * @param {number} y
 * @returns {(1 | 0)}
 */
export function equalsInt(x: number[], y: number): Bool {
  var i
  if (x[0] != y) return 0
  for (i = 1; i < x.length; i++) if (x[i]) return 0
  return 1
}

/**
 * are bigints x and y equal?
 *
 * this works even if x and y are different lengths and have arbitrarily many leading zeros
 *
 * @param {number[]} x
 * @param {number[]} y
 * @returns {(1 | 0)}
 */
export function equals(x: number[], y: number[]): Bool {
  var i
  var k = x.length < y.length ? x.length : y.length
  for (i = 0; i < k; i++) if (x[i] !== y[i]) return 0
  if (x.length > y.length) {
    for (; i < x.length; i++) if (x[i]) return 0
  } else {
    for (; i < y.length; i++) if (y[i]) return 0
  }
  return 1
}

/**
 * is the bigInt x equal to zero?
 *
 * @export
 * @param {number[]} x
 * @returns {(1 | 0)}
 */
export function isZero(x: number[]): Bool {
  var i
  for (i = 0; i < x.length; i++) if (x[i]) return 0
  return 1
}

/**
 * Convert a bigInt into a string in a given base, from base 2 up to base 95.
 *
 * Base -1 prints the contents of the array representing the number.
 *
 * @export
 * @param {number[]} x
 * @param {number} base
 * @returns {string}
 */
export function bigInt2str(x: number[], base: number): string {
  var i,
      t,
      s = ''

  if (s6.length !== x.length) s6 = dup(x)
  else copy_(s6, x)

  if (base === -1) {
    //return the list of array contents
    for (i = x.length - 1; i > 0; i--) s += x[i] + ','
    s += x[0]
  } else {
    //return it in the given base
    while (!isZero(s6)) {
      t = divInt_(s6, base) //t=s6 % base; s6=floor(s6/base);
      s = digitsStr.substring(t, t + 1) + s
    }
  }
  if (s.length === 0) s = '0'
  return s
}

/**
 * Convert a bigInt into bytes
 * @param x bigInt
 * @param littleEndian byte order by default
 */
export function bigInt2bytes(x: number[], littleEndian = true) {
  if(s6.length !== x.length) s6 = dup(x);
  else copy_(s6, x);

  const out: number[] = [];

  //console.log('bigInt2bytes');
  while(!isZero(s6)) {
    t = divInt_(s6, 256); //t=s6 % base; s6=floor(s6/base);
    out.push(t);
    //console.log('bigInt2bytes', t);
  }

  if(littleEndian) {
    out.reverse();
  }

  //console.log('bigInt2bytes', out);

  return out;
}

/**
 * Compare two bigInts and return -1 if x is less, 0 if equals, 1 if greater
 * @param x bigInt
 * @param y bigInt
 */
export function cmp(x: number[], y: number[]) {
  return greater(x, y) ? 1 : (equals(x, y) ? 0 : -1);
}

/* Object.assign(self, {
  cmp,
  str2bigInt,
  int2bigInt,
  bigInt2str,
  one,
  divide_,
  divInt_,
  dup,
  negative
}); */

/**
 * Returns a duplicate of bigInt x
 *
 * @export
 * @param {number[]} x
 * @returns {number[]}
 */
export function dup(x: number[]): number[] {
  var i
  buff = Array(x.length)
  copy_(buff, x)
  return buff
}

/**
 * do x=y on bigInts x and y.
 *
 * x must be an array at least as big as y (not counting the leading zeros in y).
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @returns {void}
 */
export function copy_(x: number[], y: number[]): void {
  var i
  var k = x.length < y.length ? x.length : y.length
  for (i = 0; i < k; i++) x[i] = y[i]
  for (i = k; i < x.length; i++) x[i] = 0
}

/**
 * do x=y on bigInt x and integer y.
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 * @returns {void}
 */
export function copyInt_(x: number[], n: number): void {
  var i, c
  var len = x.length //TODO .length in for loop have perfomance costs. Bench this
  for (c = n, i = 0; i < len; i++) {
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x+n where x is a bigInt and n is an integer.
 *
 * x must be large enough to hold the result.
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 * @returns {void}
 */
export function addInt_(x: number[], n: number): void {
  var i, k, c, b
  x[0] += n
  k = x.length
  c = 0
  for (i = 0; i < k; i++) {
    c += x[i]
    b = 0
    if (c < 0) {
      b = -(c >> bpe)
      c += b * radix
    }
    x[i] = c & mask
    c = (c >> bpe) - b
    if (!c) return //stop carrying as soon as the carry is zero
  }
}

/**
 * right shift bigInt x by n bits.
 *
 *     0 <= n < bpe.
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 */
export function rightShift_(x: number[], n: number): void {
  var i
  var k = Math.floor(n / bpe)
  if (k) {
    for (
      i = 0;
      i < x.length - k;
      i++ //right shift x by k elements
    )
      x[i] = x[i + k]
    for (; i < x.length; i++) x[i] = 0
    //$off
    n %= bpe
  }
  for (i = 0; i < x.length - 1; i++) {
    x[i] = mask & ((x[i + 1] << (bpe - n)) | (x[i] >> n))
  }
  x[i] >>= n
}

/**
 * do x=floor(|x|/2)*sgn(x) for bigInt x in 2's complement
 *
 * @param {number[]} x
 * @returns {void}
 */
export function halve_(x: number[]): void {
  var i
  for (i = 0; i < x.length - 1; i++) {
    x[i] = mask & ((x[i + 1] << (bpe - 1)) | (x[i] >> 1))
  }
  x[i] = (x[i] >> 1) | (x[i] & (radix >> 1)) //most significant bit stays the same
}

/**
 * left shift bigInt x by n bits
 *
 * @export
 * @param {number[]} x
 * @param {number} n
 * @returns {void}
 */
export function leftShift_(x: number[], n: number): void {
  var i
  var k = Math.floor(n / bpe)
  if (k) {
    for (
      i = x.length;
      i >= k;
      i-- //left shift x by k elements
    )
      x[i] = x[i - k]
    for (; i >= 0; i--) x[i] = 0
    //$off
    n %= bpe
  }
  if (!n) return
  for (i = x.length - 1; i > 0; i--) {
    x[i] = mask & ((x[i] << n) | (x[i - 1] >> (bpe - n)))
  }
  x[i] = mask & (x[i] << n)
}

/**
 * do x=x*n where x is a bigInt and n is an integer.
 *
 * x must be large enough to hold the result.
 *
 * @param {number[]} x
 * @param {number} n
 * @returns {void}
 */
export function multInt_(x: number[], n: number): void {
  var i, k, c, b
  if (!n) return
  k = x.length
  c = 0
  for (i = 0; i < k; i++) {
    c += x[i] * n
    b = 0
    if (c < 0) {
      b = -(c >> bpe)
      c += b * radix
    }
    x[i] = c & mask
    c = (c >> bpe) - b
  }
}

/**
 * do x=floor(x/n) for bigInt x and integer n, and return the remainder
 *
 * @param {number[]} x
 * @param {number} n
 * @returns {number} remainder
 */
export function divInt_(x: number[], n: number): number {
  var i,
      r = 0,
      s
  for (i = x.length - 1; i >= 0; i--) {
    s = r * radix + x[i]
    x[i] = Math.floor(s / n)
    r = s % n
  }
  return r
}

/**
 * do the linear combination x=a*x+b*y for bigInts x and y, and integers a and b.
 *
 * x must be large enough to hold the answer.
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number} a
 * @param {number} b
 * @returns {void}
 */
export function linComb_(x: number[], y: number[], a: number, b: number): void {
  var i, c, k, kk
  k = x.length < y.length ? x.length : y.length
  kk = x.length
  for (c = 0, i = 0; i < k; i++) {
    c += a * x[i] + b * y[i]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; i < kk; i++) {
    c += a * x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do the linear combination x=a*x+b*(y<<(ys*bpe)) for bigInts x and y, and integers a, b and ys.
 *
 * x must be large enough to hold the answer.
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number} b
 * @param {number} ys
 * @returns {void}
 */
export function linCombShift_(
  x: number[],
  y: number[],
  b: number,
  ys: number,
): void {
  var i, c, k, kk
  k = x.length < ys + y.length ? x.length : ys + y.length
  kk = x.length
  for (c = 0, i = ys; i < k; i++) {
    c += x[i] + b * y[i - ys]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; c && i < kk; i++) {
    c += x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x+(y<<(ys*bpe)) for bigInts x and y, and integer ys.
 *
 * x must be large enough to hold the answer.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number} ys
 * @return {void}
 */
export function addShift_(x: number[], y: number[], ys: number): void {
  var i, c, k, kk
  k = x.length < ys + y.length ? x.length : ys + y.length
  kk = x.length
  for (c = 0, i = ys; i < k; i++) {
    c += x[i] + y[i - ys]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; c && i < kk; i++) {
    c += x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x-(y<<(ys*bpe)) for bigInts x and y, and integer ys
 *
 * x must be large enough to hold the answer
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number} ys
 * @return {void}
 */
export function subShift_(x: number[], y: number[], ys: number): void {
  var i, c, k, kk
  k = x.length < ys + y.length ? x.length : ys + y.length
  kk = x.length
  for (c = 0, i = ys; i < k; i++) {
    c += x[i] - y[i - ys]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; c && i < kk; i++) {
    c += x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x-y for bigInts x and y
 *
 * x must be large enough to hold the answer
 *
 * negative answers will be 2s complement
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @return {void}
 */
export function sub_(x: number[], y: number[]): void {
  var i, c, k, kk
  k = x.length < y.length ? x.length : y.length
  for (c = 0, i = 0; i < k; i++) {
    c += x[i] - y[i]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; c && i < x.length; i++) {
    c += x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x+y for bigInts x and y
 *
 * x must be large enough to hold the answer
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @return {void}
 */
export function add_(x: number[], y: number[]): void {
  var i, c, k, kk
  k = x.length < y.length ? x.length : y.length
  for (c = 0, i = 0; i < k; i++) {
    c += x[i] + y[i]
    x[i] = c & mask
    c >>= bpe
  }
  for (i = k; c && i < x.length; i++) {
    c += x[i]
    x[i] = c & mask
    c >>= bpe
  }
}

/**
 * do x=x*y for bigInts x and y.
 *
 * This is faster when y<x.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @return {void}
 */
export function mult_(x: number[], y: number[]): void {
  var i
  if (ss.length != 2 * x.length) ss = new Array(2 * x.length)
  copyInt_(ss, 0)
  for (i = 0; i < y.length; i++) if (y[i]) linCombShift_(ss, x, y[i], i) //ss=1*ss+y[i]*(x<<(i*bpe))
  copy_(x, ss)
}

/**
 * do x=x mod n for bigInts x and n
 *
 * @export
 * @param {number[]} x
 * @param {number[]} n
 * @return {void}
 */
export function mod_(x: number[], n: number[]): void {
  if (s4.length !== x.length) s4 = dup(x)
  else copy_(s4, x)
  if (s5.length !== x.length) s5 = dup(x)
  divide_(s4, n, s5, x) //x = remainder of s4 / n
}

/**
 * do x=x*y mod n for bigInts x,y,n.
 *
 * for greater speed, let y<x.
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} n
 * @return {void}
 */
export function multMod_(x: number[], y: number[], n: number[]): void {
  var i
  if (s0.length != 2 * x.length) s0 = new Array(2 * x.length)
  copyInt_(s0, 0)
  for (i = 0; i < y.length; i++) if (y[i]) linCombShift_(s0, x, y[i], i) //s0=1*s0+y[i]*(x<<(i*bpe))
  mod_(s0, n)
  copy_(x, s0)
}

/**
 * do x=x*x mod n for bigInts x,n.
 *
 * @export
 * @param {number[]} x
 * @param {number[]} n
 * @return {void}
 */
export function squareMod_(x: number[], n: number[]): void {
  var i, j, d, c, kx, kn, k
  for (kx = x.length; kx > 0 && !x[kx - 1]; kx--); //ignore leading zeros in x
  k = kx > n.length ? 2 * kx : 2 * n.length //k=# elements in the product, which is twice the elements in the larger of x and n
  if (s0.length != k) s0 = new Array(k)
  copyInt_(s0, 0)
  for (i = 0; i < kx; i++) {
    c = s0[2 * i] + x[i] * x[i]
    s0[2 * i] = c & mask
    c >>= bpe
    for (j = i + 1; j < kx; j++) {
      c = s0[i + j] + 2 * x[i] * x[j] + c
      s0[i + j] = c & mask
      c >>= bpe
    }
    s0[i + kx] = c
  }
  mod_(s0, n)
  copy_(x, s0)
}

/**
 * return x with exactly k leading zero elements
 *
 * @export
 * @param {number[]} x
 * @param {number} k
 * @returns {number[]}
 */
export function trim(x: number[], k: number): number[] {
  var i, y
  for (i = x.length; i > 0 && !x[i - 1]; i--);
  y = new Array(i + k)
  copy_(y, x)
  return y
}

/**
 * do `x=x**y mod n`, where x,y,n are bigInts and `**` is exponentiation.  `0**0=1`.
 *
 * this is faster when n is odd.
 *
 * x usually needs to have as many elements as n.
 *
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} n
 * @return {void}
 */
export function powMod_(x: number[], y: number[], n: number[]): void {
  var k1, k2, kn, np
  if (s7.length != n.length) s7 = dup(n)

  //for even modulus, use a simple square-and-multiply algorithm,
  //rather than using the more complex Montgomery algorithm.
  if ((n[0] & 1) == 0) {
    copy_(s7, x)
    copyInt_(x, 1)
    while (!equalsInt(y, 0)) {
      if (y[0] & 1) multMod_(x, s7, n)
      divInt_(y, 2)
      squareMod_(s7, n)
    }
    return
  }

  //calculate np from n for the Montgomery multiplications
  copyInt_(s7, 0)
  for (kn = n.length; kn > 0 && !n[kn - 1]; kn--);
  np = radix - inverseModInt(modInt(n, radix), radix)
  s7[kn] = 1
  multMod_(x, s7, n) // x = x * 2**(kn*bp) mod n

  if (s3.length != x.length) s3 = dup(x)
  else copy_(s3, x)
  //$off
  // @ts-ignore
  for (k1 = y.length - 1; (k1 > 0) & !y[k1]; k1--); //k1=first nonzero element of y
  if (y[k1] == 0) {
    //anything to the 0th power is 1
    copyInt_(x, 1)
    return
  }
  for (k2 = 1 << (bpe - 1); k2 && !(y[k1] & k2); k2 >>= 1); //k2=position of first 1 bit in y[k1]
  for (;;) {
    if (!(k2 >>= 1)) {
      //look at next bit of y
      k1--
      if (k1 < 0) {
        mont_(x, one, n, np)
        return
      }
      k2 = 1 << (bpe - 1)
    }
    mont_(x, x, n, np)

    if (k2 & y[k1])
      //if next bit is a 1
      mont_(x, s3, n, np)
  }
}

/**
 * do x=x*y*Ri mod n for bigInts x,y,n,
 * where Ri = 2**(-kn*bpe) mod n, and kn is the
 * number of elements in the n array, not
 * counting leading zeros.
 *
 * x array must have at least as many elemnts as the n array
 * It's OK if x and y are the same variable.
 *
 * must have:
 *  * x,y < n
 *  * n is odd
 *  * np = -(n^(-1)) mod radix
 *
 * @export
 * @param {number[]} x
 * @param {number[]} y
 * @param {number[]} n
 * @param {number} np
 * @return {void}
 */
export function mont_(x: number[], y: number[], n: number[], np: number): void {
  var i, j, c, ui, t, ks
  var kn = n.length
  var ky = y.length

  if (sa.length != kn) sa = new Array(kn)

  copyInt_(sa, 0)

  for (; kn > 0 && n[kn - 1] == 0; kn--); //ignore leading zeros of n
  for (; ky > 0 && y[ky - 1] == 0; ky--); //ignore leading zeros of y
  ks = sa.length - 1 //sa will never have more than this many nonzero elements.

  //the following loop consumes 95% of the runtime for randTruePrime_() and powMod_() for large numbers
  for (i = 0; i < kn; i++) {
    t = sa[0] + x[i] * y[0]
    ui = ((t & mask) * np) & mask //the inner "& mask" was needed on Safari (but not MSIE) at one time
    c = (t + ui * n[0]) >> bpe
    t = x[i]

    //do sa=(sa+x[i]*y+ui*n)/b   where b=2**bpe.  Loop is unrolled 5-fold for speed
    j = 1
    for (; j < ky - 4; ) {
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
    }
    for (; j < ky; ) {
      c += sa[j] + ui * n[j] + t * y[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
    }
    for (; j < kn - 4; ) {
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
    }
    for (; j < kn; ) {
      c += sa[j] + ui * n[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
    }
    for (; j < ks; ) {
      c += sa[j]
      sa[j - 1] = c & mask
      c >>= bpe
      j++
    }
    sa[j - 1] = c & mask
  }

  if (!greater(n, sa)) sub_(sa, n)
  copy_(x, sa)
}