Write a function that takes an unsigned integer and returns the number of ’1‘ bits it has (also known as the Hamming weight).
For example, the 32-bit integer ’11‘ has binary representation 00000000000000000000000000001011, so the function should return 3.
1 class Solution { 2 public: 3 int hammingWeight(uint32_t n) { 4 5 int count = 0; 6 7 while(n) 8 { 9 n = (n & (n-1)); 10 count++; 11 } 12 return count; 13 } 14 };
原文：http://www.cnblogs.com/sankexin/p/5863929.html