日期:2014-05-16 浏览次数:20492 次
(public) Constructor function BigInteger(a, b, c) { if (a != null) if ("number" == typeof a) this.fromNumber(a, b, c); else if (b == null && "string" != typeof a) this.fromString(a, 256); else this.fromString(a, b); } // return bigint initialized to value function nbv(i) { var r = nbi(); r.fromInt(i); return r; } // return new, unset BigInteger function nbi() { return new BigInteger(null); } // (protected) set from string and radix function fromString(s, b) { var k; if (b == 16) k = 4;//k = 4 else if (b == 8) k = 3; else if (b == 256) k = 8; // byte array else if (b == 2) k = 1; else if (b == 32) k = 5; else if (b == 4) k = 2; else { this.fromRadix(s, b); return; } this.t = 0; this.s = 0; var i = s.length, mi = false, sh = 0; while (--i >= 0) { var x = (k == 8) ? s[i] & 0xff: intAt(s, i); if (x < 0) { if (s.charAt(i) == "-") mi = true; continue; } mi = false; if (sh == 0) this[this.t++] = x; else if (sh + k > this.DB) { this[this.t - 1] |= (x & ((1 << (this.DB - sh)) - 1)) << sh; this[this.t++] = (x >> (this.DB - sh)); } else this[this.t - 1] |= x << sh; sh += k; if (sh >= this.DB) sh -= this.DB; } if (k == 8 && (s[0] & 0x80) != 0) { this.s = -1; if (sh > 0) this[this.t - 1] |= ((1 << (this.DB - sh)) - 1) << sh; } this.clamp(); if (mi) BigInteger.ZERO.subTo(this, this); } function fromInt(x) { this.t = 1; this.s = (x < 0) ? -1 : 0; if (x > 0) this[0] = x; else if (x < -1) this[0] = x + DV; else this.t = 0; } BigInteger.ZERO = nbv(0); BigInteger.ONE = nbv(1);