LeetCode:191. Number of 1 Bits

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题目描述

Write a function that takes an unsigned integer and return the number of ‘1’ bits it has (also known as the Hamming weight).

Example 1:

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Input: 00000000000000000000000000001011
Output: 3
Explanation: The input binary string 00000000000000000000000000001011 has a total of three '1' bits.

Example 2:

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Input: 00000000000000000000000010000000
Output: 1
Explanation: The input binary string 00000000000000000000000010000000 has a total of one '1' bit.

Example 3:

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Input: 11111111111111111111111111111101
Output: 31
Explanation: The input binary string 11111111111111111111111111111101 has a total of thirty one '1' bits.

代码实现

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class Solution {
public:
    int hammingWeight(uint32_t n) {
        int result = 0;
        while (n > 0){
            if (n & 1) {
                result ++;
            }
            n >>= 1;
        }
        return result;
    }
};