mathball/lib/division/index.js

A JavaScript library for Competitive Programming

'use strict';

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }

/*Division operation across all data-types and data-structures
* Function: M.div(m,n)
*/
var Complex = require('../complex');
var validate = require('../validation/argument-length');

var div = function div(a, b) {
	switch (a.constructor) {
		case Number:
			return divNum(a, b);
		case String:
			return divString(a, b);
		case Array:
			if (a[0].constructor === Array) {
				return divMatrix(a, b);
			} else {
				return divArray(a, b);
			}
		case Complex:
			return divComplex(a, b);
	}
};

var divNum = function divNum(a, b) {
	return a / b;
};

var divString = function divString(a, b) {
	var div = Number(a) / Number(b);
	return div.toString(10);
};

var divArray = function divArray(a, b) {
	var div = new Array(a.length);
	for (var i = 0; i < a.length; i++) {
		var l = a[i] / b[i];
		div.push(l);
		div = div.filter(function (n) {
			return n;
		});
	}
	return div;
};

//Determinant of a matrix

function det(a, n) {
	var determinant = 0,
	    c1 = void 0,
	    c2 = void 0,
	    sign = 1;
	var detArr = [].concat(_toConsumableArray(Array(n))).map(function (x) {
		return Array(n).fill(0);
	});
	if (n === 1) {
		return a[0][0];
	} else if (n === 2) {
		determinant = a[0][0] * a[1][1] - a[0][1] * a[1][0];
		return determinant;
	} else {
		for (var i = 0; i < n; i++) {
			c1 = 0, c2 = 0;
			for (var j = 0; j < n; j++) {
				for (var k = 0; k < n; k++) {
					if (j != 0 && k != i) {
						detArr[c1][c2] = a[j][k];
						c2++;
						if (c2 > n - 2) {
							c1++;
							c2 = 0;
						}
					}
				}
			}
			determinant = determinant + sign * a[0][i] * det(detArr, n - 1);
			sign = -1 * sign;
		}
		return determinant;
	}
}
function coFactor(a, temp, p, q, n) {
	var i = 0,
	    j = 0;
	for (var row = 0; row < n; row++) {
		for (var col = 0; col < n; col++) {
			if (row !== p && col != q) {
				temp[i][j++] = a[row][col];
				if (j === n - 1) {
					j = 0;
					i++;
				}
			}
		}
	}
}
function _adjugate(a) {
	var n = a.length;
	var adj = [].concat(_toConsumableArray(Array(n))).map(function (x) {
		return Array(n).fill(0);
	});
	var temp = [].concat(_toConsumableArray(Array(n))).map(function (x) {
		return Array(n).fill(0);
	});
	if (n === 1) {
		return 1;
	}

	var sign = 1;

	for (var i = 0; i < n; i++) {
		for (var j = 0; j < n; j++) {

			coFactor(a, temp, i, j, n);
			sign = (i + j) % 2 === 0 ? 1 : -1;
			adj[j][i] = sign * det(temp, n - 1);
		}
	}
	return adj;
}

function inverse(a) {
	var n = a.length;
	var determinant = det(a, n);
	if (determinant === 0) {
		return 0;
	}
	var inv = [].concat(_toConsumableArray(Array(n))).map(function (x) {
		return Array(n).fill(0);
	});
	var adj = _adjugate(a);

	if (adj === 1) {
		return 1;
	}

	for (var i = 0; i < n; i++) {
		for (var j = 0; j < n; j++) {
			inv[i][j] = Number(parseFloat(adj[i][j] / determinant).toFixed(2));
		}
	}
	return inv;
}

var divMatrix = function divMatrix(a, b) {
	b = inverse(b);
	if (b === 0) {
		return 0;
	}

	if (b === 1) {
		return 1;
	}

	var div = [].concat(_toConsumableArray(Array(a.length))).map(function (x) {
		return Array(a[0].length).fill(0);
	});
	for (var i = 0; i < a.length; i++) {
		for (var j = 0; j < b.length; j++) {
			var sum = 0;
			for (var k = 0; k < a[0].length; k++) {
				var pro = a[i][k] * b[k][j];
				sum = Math.round(sum + pro);
			}
			div[i][j] = sum;
		}
	}
	return div;
};

var divComplex = function divComplex(a, b) {
	var div = {
		re: 0,
		im: 0
	};
	var dm = Math.pow(b.re, 2) + Math.pow(b.im, 2);
	div.re = parseFloat(((a.re * b.re + a.im * b.re) / dm).toFixed(2));
	div.im = parseFloat(((b.re * a.im - a.re * b.im) / dm).toFixed(2));
	return div;
};

module.exports = function () {
	for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
		args[_key] = arguments[_key];
	}

	if (args.length > 2) {
		throw new TypeError('Invalid argument received: ' + JSON.stringify(args) + '\n\'div()\' only accepts two parameters!\n');
	}
	validate(args);
	return div(args[0], args[1]);
};