2595. Number of Even and Odd Bits

problem

solution

class Solution {
public:
    vector<int> evenOddBit(int n) {
        vector<int> ret(2,0);
        int idx = 0;
        while(n){
            ret[idx%2]+=n&1; 
            n>>=1;
            idx++;
        }
        return ret;
    }
};

analysis

• time complexity O(logn)
• space complexity O(1)