#Leetcode# 191. Number of 1 Bits

https://leetcode.com/problems/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).

Example 1:

Input: 11
Output: 3
Explanation: Integer 11 has binary representation 00000000000000000000000000001011 

Example 2:

Input: 128
Output: 1
Explanation: Integer 128 has binary representation 00000000000000000000000010000000

代码：

class Solution {
public:
    int hammingWeight(uint32_t n) {
        vector<int> v;
        while(n) {
            v.push_back(n % 2);
            n /= 2;
        }
        
        int ans = 0;
        for(int i = 0; i < v.size(); i ++) {
            if(v[i])
                ans ++;
        }
        
        return ans;
    }
};