mathjs/lib/esm/function/arithmetic/gcd.js

import { factory } from '../../utils/factory.js';
import { createAlgorithm01 } from '../../type/matrix/utils/algorithm01.js';
import { createAlgorithm04 } from '../../type/matrix/utils/algorithm04.js';
import { createAlgorithm10 } from '../../type/matrix/utils/algorithm10.js';
import { createAlgorithm13 } from '../../type/matrix/utils/algorithm13.js';
import { createAlgorithm14 } from '../../type/matrix/utils/algorithm14.js';
import { gcdNumber } from '../../plain/number/index.js';
var name = 'gcd';
var dependencies = ['typed', 'matrix', 'equalScalar', 'BigNumber', 'DenseMatrix'];
export var createGcd = /* #__PURE__ */factory(name, dependencies, (_ref) => {
  var {
    typed,
    matrix,
    equalScalar,
    BigNumber,
    DenseMatrix
  } = _ref;
  var algorithm01 = createAlgorithm01({
    typed
  });
  var algorithm04 = createAlgorithm04({
    typed,
    equalScalar
  });
  var algorithm10 = createAlgorithm10({
    typed,
    DenseMatrix
  });
  var algorithm13 = createAlgorithm13({
    typed
  });
  var algorithm14 = createAlgorithm14({
    typed
  });
  /**
   * Calculate the greatest common divisor for two or more values or arrays.
   *
   * For matrices, the function is evaluated element wise.
   *
   * Syntax:
   *
   *    math.gcd(a, b)
   *    math.gcd(a, b, c, ...)
   *
   * Examples:
   *
   *    math.gcd(8, 12)              // returns 4
   *    math.gcd(-4, 6)              // returns 2
   *    math.gcd(25, 15, -10)        // returns 5
   *
   *    math.gcd([8, -4], [12, 6])   // returns [4, 2]
   *
   * See also:
   *
   *    lcm, xgcd
   *
   * @param {... number | BigNumber | Fraction | Array | Matrix} args  Two or more integer numbers
   * @return {number | BigNumber | Fraction | Array | Matrix}                           The greatest common divisor
   */

  return typed(name, {
    'number, number': gcdNumber,
    'BigNumber, BigNumber': _gcdBigNumber,
    'Fraction, Fraction': function FractionFraction(x, y) {
      return x.gcd(y);
    },
    'SparseMatrix, SparseMatrix': function SparseMatrixSparseMatrix(x, y) {
      return algorithm04(x, y, this);
    },
    'SparseMatrix, DenseMatrix': function SparseMatrixDenseMatrix(x, y) {
      return algorithm01(y, x, this, true);
    },
    'DenseMatrix, SparseMatrix': function DenseMatrixSparseMatrix(x, y) {
      return algorithm01(x, y, this, false);
    },
    'DenseMatrix, DenseMatrix': function DenseMatrixDenseMatrix(x, y) {
      return algorithm13(x, y, this);
    },
    'Array, Array': function ArrayArray(x, y) {
      // use matrix implementation
      return this(matrix(x), matrix(y)).valueOf();
    },
    'Array, Matrix': function ArrayMatrix(x, y) {
      // use matrix implementation
      return this(matrix(x), y);
    },
    'Matrix, Array': function MatrixArray(x, y) {
      // use matrix implementation
      return this(x, matrix(y));
    },
    'SparseMatrix, number | BigNumber': function SparseMatrixNumberBigNumber(x, y) {
      return algorithm10(x, y, this, false);
    },
    'DenseMatrix, number | BigNumber': function DenseMatrixNumberBigNumber(x, y) {
      return algorithm14(x, y, this, false);
    },
    'number | BigNumber, SparseMatrix': function numberBigNumberSparseMatrix(x, y) {
      return algorithm10(y, x, this, true);
    },
    'number | BigNumber, DenseMatrix': function numberBigNumberDenseMatrix(x, y) {
      return algorithm14(y, x, this, true);
    },
    'Array, number | BigNumber': function ArrayNumberBigNumber(x, y) {
      // use matrix implementation
      return algorithm14(matrix(x), y, this, false).valueOf();
    },
    'number | BigNumber, Array': function numberBigNumberArray(x, y) {
      // use matrix implementation
      return algorithm14(matrix(y), x, this, true).valueOf();
    },
    // TODO: need a smarter notation here
    'Array | Matrix | number | BigNumber, Array | Matrix | number | BigNumber, ...Array | Matrix | number | BigNumber': function ArrayMatrixNumberBigNumberArrayMatrixNumberBigNumberArrayMatrixNumberBigNumber(a, b, args) {
      var res = this(a, b);

      for (var i = 0; i < args.length; i++) {
        res = this(res, args[i]);
      }

      return res;
    }
  });
  /**
   * Calculate gcd for BigNumbers
   * @param {BigNumber} a
   * @param {BigNumber} b
   * @returns {BigNumber} Returns greatest common denominator of a and b
   * @private
   */

  function _gcdBigNumber(a, b) {
    if (!a.isInt() || !b.isInt()) {
      throw new Error('Parameters in function gcd must be integer numbers');
    } // https://en.wikipedia.org/wiki/Euclidean_algorithm


    var zero = new BigNumber(0);

    while (!b.isZero()) {
      var r = a.mod(b);
      a = b;
      b = r;
    }

    return a.lt(zero) ? a.neg() : a;
  }
});