dsa-competitive-programming/leetcode/lc401/enumerateHrsMins.cpp

class Solution{
    public : 
        vector<string> readBinaryWatch(int turnedOn){
            vector<string> ans;
            for(int h=0;h<12;++h){
                for(int m = 0;m<60;++m){
                    if(__builtin_popcount(h)+ __builtin_popcount(m) == turnedOn){
                        ans.push_back(to_string(h)+":"+(m<10?"0":"")+to_string(m));
                    }
                }
            }
            return ans;
        }
}