【Leetcode Bit Operation C++】338. Counting Bits

338. Counting Bits

class Solution {
    
    
public:
    vector<int> countBits(int num) {
    
    
        vector<int> V;
        V.push_back(0);
        for(int ii = 1; ii <= num; ii++) {
    
    
            int cnt = 0;
            for(int bit = 1; bit <= ii; bit <<= 1) if(ii & bit) cnt++;
            V.push_back(cnt);
        }
        return V;
    }
};