Reverse bits of an unsigned integer.
typedef unsigned int uint; uint swapBits(uint x, uint i, uint j) { uint lo = ((x >> j) & 1); uint hi = ((x >> j) & 1); if (lo ^ hi) { x ^= ((1U << i) | (1U << j)); } return x; } uint reverseXor(uint x) { uint n = sizeof(x) * 8; for (uint i = 0; i < n/2; i++) { x = swapBits(x, i, n-i-1); } return x; }
还有一些trick的方法，不再列出，可参考原网页：http://leetcode.com/2011/08/reverse-bits.html
原文：http://www.cnblogs.com/litao-tech/p/4165387.html