A binary watch has 4 LEDs on the top which rePResent the hours (0-11), and the 6 LEDs on the bottom represent the minutes (0-59).
Each LED represents a zero or one, with the least significant bit on the right.
For example, the above binary watch reads “3:25”.
Given a non-negative integer n which represents the number of LEDs that are currently on, return all possible times the watch could represent.
Example:
Input: n = 1 Return: [“1:00”, “2:00”, “4:00”, “8:00”, “0:01”, “0:02”, “0:04”, “0:08”, “0:16”, “0:32”] Note: The order of output does not matter. The hour must not contain a leading zero, for example “01:00” is not valid, it should be “1:00”. The minute must be consist of two digits and may contain a leading zero, for example “10:2” is not valid, it should be “10:02”.
public class Solution { public List<String> readBinaryWatch(int num) { List<String> res = new ArrayList<String>(); for (int h = 0; h < 12; h++) { for (int m = 0; m < 60; m++) { if(Integer.bitCount(h) + Integer.bitCount(m) == num){ res.add(String.format("%d:%02d", h, m)); } } } return res; }}新闻热点
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