LeetCode : Number of 1 Bits

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 sum = 0;
        while(n)
        {
            sum++;
            n&=n-1;
        }
        return sum;
    }
};

posted on 2017-03-15 16:32  gechen  阅读(81)  评论(0编辑  收藏  举报

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