191. Number of 1 Bits (Int; Bit)

weixin_30466421

于 2015-12-16 12:37:00 发布

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原文链接：http://www.cnblogs.com/qionglouyuyu/p/5050807.html

本文介绍了一个C++函数，该函数用于计算一个无符号32位整数中二进制表示的‘1’的数量，即汉明重量。通过遍历整数的每一位并检查是否为1来实现。

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.

class Solution {
public:
    int hammingWeight(uint32_t n) {
        int ret = 0;
        for (unsigned int i = 1; i != 0; i <<= 1){
            if(n & 1) ret++;
            n >>= 1;
        }
        return ret;
    }
};