401. Binary Watch
java代码:
public class Solution { public List<String> readBinaryWatch(int num) { List<String> times=new ArrayList<>(); for(int h=0;h<12;h++){ for(int m=0;m<60;m++){ if(Integer.bitCount(h*64+m)==num) times.add(String.format("%d:%02d",h,m)); } } return times; } }