big.js

//https://github.com/MikeMcl/big.js
;(function(global) {
	'use strict';
	var DP = 20,
		RM = 1,
		MAX_DP = 1E6,
		MAX_POWER = 1E6,
		E_NEG = -7,
		E_POS = 21,
		P = {},
		isValid = /^-?(\d+(\.\d*)?|\.\d+)(e[+-]?\d+)?$/i,
		Big;
	function bigFactory() {
		function Big(n) {
			var x = this;
			if (!(x instanceof Big))
				return n === void 0 ? bigFactory() : new Big(n);
			if (n instanceof Big) {
				x.s = n.s;
				x.e = n.e;
				x.c = n.c.slice();
			} else
				parse(x, n);
			x.constructor = Big;
		}
		Big.prototype = P;
		Big.DP = DP;
		Big.RM = RM;
		Big.E_NEG = E_NEG;
		Big.E_POS = E_POS;
		return Big;
	}
	function format(x, dp, toE) {
		var Big = x.constructor,
			i = dp - (x = new Big(x)).e,
			c = x.c;
		if (c.length > ++dp)
			rnd(x, i, Big.RM);
		if (!c[0])
			++i;
		else if (toE)
			i = dp;
		else {
			c = x.c;
			i = x.e + i + 1;
		}
		for (; c.length < i; c.push(0));
		i = x.e;
		return toE === 1 || toE && (dp <= i || i <= Big.E_NEG) ?
			(x.s < 0 && c[0] ? '-' : '') +
				(c.length > 1 ? c[0] + '.' + c.join('').slice(1) : c[0]) +
				(i < 0 ? 'e' : 'e+') + i
			: x.toString();
	}
	function parse(x, n) {
		var e, i, nL;
		if (n === 0 && 1 / n < 0)
			n = '-0';
		else if (!isValid.test(n += ''))
			throwErr(NaN);
		x.s = n[0] == '-' ? (n = n.slice(1), -1) : 1;
		if ((e = n.indexOf('.')) > -1)
			n = n.replace('.', '');
		if ((i = n.search(/e/i)) > 0) {
			if (e < 0)
				e = i;
			e += +n.slice(i + 1);
			n = n.substring(0, i);
		} else if (e < 0)
			e = n.length;
		for (i = 0; n.charAt(i) == '0'; i++);
		if (i == (nL = n.length))
			x.c = [ x.e = 0 ];
		else {
			for (; n.charAt(--nL) == '0';);
			x.e = e - i - 1;
			x.c = [];
			for (e = 0; i <= nL; x.c[e++] = +n.charAt(i++));
		}
		return x;
	}
	function rnd(x, dp, rm, more) {
		var u,
			xc = x.c,
			i = x.e + dp + 1;
		if (rm === 1)
			more = xc[i] >= 5;
		else if (rm === 2)
			more = xc[i] > 5 || xc[i] == 5 &&
				(more || i < 0 || xc[i + 1] !== u || xc[i - 1] & 1);
		else if (rm === 3)
			more = more || xc[i] !== u || i < 0;
		else {
			more = false;
			if (rm)
				throwErr('!Big.RM!');
		}
		if (i < 1 || !xc[0]) {
			if (more) {
				x.e = -dp;
				x.c = [1];
			} else
				x.c = [x.e = 0];
		} else {
			xc.length = i--;
			if (more) {
				for (; ++xc[i] > 9;) {
					xc[i] = 0;
					if (!i--) {
						++x.e;
						xc.unshift(1);
					}
				}
			}
			for (i = xc.length; !xc[--i]; xc.pop());
		}
		return x;
	}
	function throwErr(message) {
		var err = new Error(message);
		err.name = 'BigError';
		throw err;
	}
	P.abs = function() {
		var x = new this.constructor(this);
		x.s = 1;
		return x;
	};
	P.cmp = function(y) {
		var xNeg,
			x = this,
			xc = x.c,
			yc = (y = new x.constructor(y)).c,
			i = x.s,
			j = y.s,
			k = x.e,
			l = y.e;
		if (!xc[0] || !yc[0])
			return !xc[0] ? !yc[0] ? 0 : -j : i;
		if (i != j)
			return i;
		xNeg = i < 0;
		if (k != l)
			return k > l ^ xNeg ? 1 : -1;
		i = -1;
		j = (k = xc.length) < (l = yc.length) ? k : l;
		for (; ++i < j;)
			if (xc[i] != yc[i])
				return xc[i] > yc[i] ^ xNeg ? 1 : -1;
		return k == l ? 0 : k > l ^ xNeg ? 1 : -1;
	};
	P.div = function(y) {
		var x = this,
			Big = x.constructor,
			dvd = x.c,
			dvs = (y = new Big(y)).c,
			s = x.s == y.s ? 1 : -1,
			dp = Big.DP;
		if (dp !== ~~dp || dp < 0 || dp > MAX_DP)
			throwErr('!Big.DP!');
		if (!dvd[0] || !dvs[0]) {
			if (dvd[0] == dvs[0])
			if (!dvs[0])
				throwErr(s / 0);
			return new Big(s * 0);
		}
		var dvsL, dvsT, next, cmp, remI, u,
			dvsZ = dvs.slice(),
			dvdI = dvsL = dvs.length,
			dvdL = dvd.length,
			rem = dvd.slice(0, dvsL),
			remL = rem.length,
			q = y,
			qc = q.c = [],
			qi = 0,
			digits = dp + (q.e = x.e - y.e) + 1;
		q.s = s;
		s = digits < 0 ? 0 : digits;
		dvsZ.unshift(0);
		for (; remL++ < dvsL; rem.push(0));
		do {
			for (next = 0; next < 10; next++) {
				if (dvsL != (remL = rem.length))
					cmp = dvsL > remL ? 1 : -1;
				else
					for (remI = -1, cmp = 0; ++remI < dvsL;)
						if (dvs[remI] != rem[remI]) {
							cmp = dvs[remI] > rem[remI] ? 1 : -1;
							break;
						}
				if (cmp < 0) {
					for (dvsT = remL == dvsL ? dvs : dvsZ; remL;) {
						if (rem[--remL] < dvsT[remL]) {
							remI = remL;
							for (; remI && !rem[--remI]; rem[remI] = 9);
							--rem[remI];
							rem[remL] += 10;
						}
						rem[remL] -= dvsT[remL];
					}
					for (; !rem[0]; rem.shift());
				} else
					break;
			}
			qc[qi++] = cmp ? next : ++next;
			if (rem[0] && cmp)
				rem[remL] = dvd[dvdI] || 0;
			else
				rem = [dvd[dvdI]];
		} while ((dvdI++ < dvdL || rem[0] !== u) && s--);
		if (!qc[0] && qi != 1) {
			qc.shift();
			q.e--;
		}
		if (qi > digits)
			rnd(q, dp, Big.RM, rem[0] !== u);
		return q;
	};
	P.eq = function(y) {
		return !this.cmp(y);
	};
	P.gt = function(y) {
		return this.cmp(y) > 0;
	};
	P.gte = function(y) {
		return this.cmp(y) > -1;
	};
	P.lt = function(y) {
		return this.cmp(y) < 0;
	};
	P.lte = function(y) {
		 return this.cmp(y) < 1;
	};
	P.sub = P.minus = function(y) {
		var i, j, t, xLTy,
			x = this,
			Big = x.constructor,
			a = x.s,
			b = (y = new Big(y)).s;
		if (a != b) {
			y.s = -b;
			return x.plus(y);
		}
		var xc = x.c.slice(),
			xe = x.e,
			yc = y.c,
			ye = y.e;
		if (!xc[0] || !yc[0])
			return yc[0] ? (y.s = -b, y) : new Big(xc[0] ? x : 0);
		if (a = xe - ye) {
			if (xLTy = a < 0) {
				a = -a;
				t = xc;
			} else {
				ye = xe;
				t = yc;
			}
			t.reverse();
			for (b = a; b--; t.push(0));
			t.reverse();
		} else {
			j = ((xLTy = xc.length < yc.length) ? xc : yc).length;
			for (a = b = 0; b < j; b++)
				if (xc[b] != yc[b]) {
					xLTy = xc[b] < yc[b];
					break;
				}
		}
		if (xLTy) {
			t = xc;
			xc = yc;
			yc = t;
			y.s = -y.s;
		}
		if (( b = (j = yc.length) - (i = xc.length) ) > 0)
			for (; b--; xc[i++] = 0);
		for (b = i; j > a;){
			if (xc[--j] < yc[j]) {
				for (i = j; i && !xc[--i]; xc[i] = 9);
				--xc[i];
				xc[j] += 10;
			}
			xc[j] -= yc[j];
		}
		for (; xc[--b] === 0; xc.pop());
		for (; xc[0] === 0;) {
			xc.shift();
			--ye;
		}
		if (!xc[0]) {
			y.s = 1;
			xc = [ye = 0];
		}
		y.c = xc;
		y.e = ye;
		return y;
	};
	P.mod = function(y) {
		var yGTx,
			x = this,
			Big = x.constructor,
			a = x.s,
			b = (y = new Big(y)).s;
		if (!y.c[0])
			throwErr(NaN);
		x.s = y.s = 1;
		yGTx = y.cmp(x) == 1;
		x.s = a;
		y.s = b;
		if (yGTx)
			return new Big(x);
		a = Big.DP;
		b = Big.RM;
		Big.DP = Big.RM = 0;
		x = x.div(y);
		Big.DP = a;
		Big.RM = b;
		return this.minus( x.times(y) );
	};
	P.add = P.plus = function(y) {
		var t,
			x = this,
			Big = x.constructor,
			a = x.s,
			b = (y = new Big(y)).s;
		if (a != b) {
			y.s = -b;
			return x.minus(y);
		}
		var xe = x.e,
			xc = x.c,
			ye = y.e,
			yc = y.c;
		if (!xc[0] || !yc[0])
			return yc[0] ? y : new Big(xc[0] ? x : a * 0);
		xc = xc.slice();
		if (a = xe - ye) {
			if (a > 0) {
				ye = xe;
				t = yc;
			} else {
				a = -a;
				t = xc;
			}
			t.reverse();
			for (; a--; t.push(0)) {
			}
			t.reverse();
		}
		if (xc.length - yc.length < 0) {
			t = yc;
			yc = xc;
			xc = t;
		}
		a = yc.length;
		for (b = 0; a;) {
			b = (xc[--a] = xc[a] + yc[a] + b) / 10 | 0;
			xc[a] %= 10;
		}
		if (b) {
			xc.unshift(b);
			++ye;
		}
		for (a = xc.length; xc[--a] === 0; xc.pop());
		y.c = xc;
		y.e = ye;
		return y;
	};
	P.pow = function(n) {
		var x = this,
			one = new x.constructor(1),
			y = one,
			isNeg = n < 0;
		if (n !== ~~n || n < -MAX_POWER || n > MAX_POWER)
			throwErr('!pow!');
		n = isNeg ? -n : n;
		for (;;) {
			if (n & 1)
				y = y.times(x);
			n >>= 1;
			if (!n)
				break;
			x = x.times(x);
		}
		return isNeg ? one.div(y) : y;
	};


	/*
	 * Return a new Big whose value is the value of this Big rounded to a
	 * maximum of dp decimal places using rounding mode rm.
	 * If dp is not specified, round to 0 decimal places.
	 * If rm is not specified, use Big.RM.
	 *
	 * [dp] {number} Integer, 0 to MAX_DP inclusive.
	 * [rm] 0, 1, 2 or 3 (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_UP)
	 */
	P.round = function(dp, rm) {
		var x = this,
			Big = x.constructor;
		if (dp == null)
			dp = 0;
		else if (dp !== ~~dp || dp < 0 || dp > MAX_DP)
			throwErr('!round!');
		rnd(x = new Big(x), dp, rm == null ? Big.RM : rm);
		return x;
	};
	P.sqrt = function() {
		var estimate, r, approx,
			x = this,
			Big = x.constructor,
			xc = x.c,
			i = x.s,
			e = x.e,
			half = new Big('0.5');
		if (!xc[0])
			return new Big(x);
		if (i < 0)
			throwErr(NaN);
		i = Math.sqrt(x.toString());
		if (i === 0 || i === 1 / 0) {
			estimate = xc.join('');
			if (!(estimate.length + e & 1))
				estimate += '0';
			r = new Big(Math.sqrt(estimate).toString());
			r.e = ((e + 1) / 2 | 0) - (e < 0 || e & 1);
		} else
			r = new Big(i.toString());
		i = r.e + (Big.DP += 4);
		do {
			approx = r;
			r = half.times( approx.plus( x.div(approx) ) );
		} while (approx.c.slice(0, i).join('') !== r.c.slice(0, i).join(''));
		rnd(r, Big.DP -= 4, Big.RM);
		return r;
	};
	P.mul = P.times = function(y) {
		var c,
			x = this,
			Big = x.constructor,
			xc = x.c,
			yc = (y = new Big(y)).c,
			a = xc.length,
			b = yc.length,
			i = x.e,
			j = y.e;
		y.s = x.s == y.s ? 1 : -1;
		if (!xc[0] || !yc[0]) {
			return new Big(y.s * 0);
		}
		y.e = i + j;
		if (a < b) {
			c = xc;
			xc = yc;
			yc = c;
			j = a;
			a = b;
			b = j;
		}
		for (c = new Array(j = a + b); j--; c[j] = 0);
		for (i = b; i--;) {
			b = 0;
			for (j = a + i; j > i;) {
				b = c[j] + yc[i] * xc[j - i - 1] + b;
				c[j--] = b % 10;
				b = b / 10 | 0;
			}
			c[j] = (c[j] + b) % 10;
		}
		if (b)
			++y.e;
		if (!c[0])
			c.shift();
		for (i = c.length; !c[--i]; c.pop());
		y.c = c;
		return y;
	};
	P.toString = P.valueOf = P.toJSON = function() {
		var x = this,
			Big = x.constructor,
			e = x.e,
			str = x.c.join(''),
			strL = str.length;
		if (e <= Big.E_NEG || e >= Big.E_POS) {
			str = str.charAt(0) + (strL > 1 ? '.' + str.slice(1) : '') +
				(e < 0 ? 'e' : 'e+') + e;
		} else if (e < 0) {
			for (; ++e; str = '0' + str);
			str = '0.' + str;
		} else if (e > 0) {
			if (++e > strL)
				for (e -= strL; e-- ; str += '0');
			else if (e < strL)
				str.slice(0, e) + '.' + str.slice(e);
		} else if (strL > 1)
			str = str.charAt(0) + '.' + str.slice(1);
		return x.s < 0 && x.c[0] ? '-' + str : str;
	};
	P.toExponential = function(dp) {
		if (dp == null)
			dp = this.c.length - 1;
		else if (dp !== ~~dp || dp < 0 || dp > MAX_DP)
			throwErr('!toExp!');
		return format(this, dp, 1);
	};
	P.toFixed = function(dp) {
		var str,
			x = this,
			Big = x.constructor,
			neg = Big.E_NEG,
			pos = Big.E_POS;
		Big.E_NEG = -(Big.E_POS = 1 / 0);
		if (dp == null)
			str = x.toString();
		else if (dp === ~~dp && dp >= 0 && dp <= MAX_DP) {
			str = format(x, x.e + dp);
			if (x.s < 0 && x.c[0] && str.indexOf('-') < 0)
				str = '-' + str;
		}
		Big.E_NEG = neg;
		Big.E_POS = pos;
		if (!str)
			throwErr('!toFix!');
		return str;
	};
	P.toPrecision = function(sd) {
		if (sd == null)
			return this.toString();
		else if (sd !== ~~sd || sd < 1 || sd > MAX_DP)
			throwErr('!toPre!');
		return format(this, sd - 1, 2);
	};
	Big = bigFactory();
	if (typeof define === 'function' && define.amd)
		define(function() { return Big; });
	else if (typeof module !== 'undefined' && module.exports)
		module.exports = Big;
	else
		global.Big = Big;
})(this);