Leetcode 681. Next Closest Time

Given a time represented in the format "HH:MM", form the next closest time by reusing the current digits. There is no limit on how many times a digit can be reused.

You may assume the given input string is always valid. For example, "01:34", "12:09" are all valid. "1:34", "12:9" are all invalid.

Example 1:

Input: "19:34"
Output: "19:39"
Explanation: The next closest time choosing from digits 1, 9, 3, 4, is 19:39, which occurs 5 minutes later.  It is not 19:33, because this occurs 23 hours and 59 minutes later.

Example 2:

Input: "23:59"
Output: "22:22"
Explanation: The next closest time choosing from digits 2, 3, 5, 9, is 22:22. It may be assumed that the returned time is next day's time since it is smaller than the input time numerically.

Code (Java):

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

class Solution {     public String nextClosestTime(String time) {         int original = getElapsedMinutes(time);         int minDiff = Integer.MAX_VALUE;         int ans = original;           Set<Integer> set = new HashSet<>();         for (int i = 0; i < time.length(); i++) {             if (time.charAt(i) != ':') {                 set.add(Character.getNumericValue(time.charAt(i)));             }         }           for (int h1 : set) {             for (int h2 : set) {                 if (h1 * 10 + h2 < 24) {                     for (int m1 : set) {                         for (int m2 : set) {                             if (m1 * 10 + m2 < 60) {                                 int currTime = (h1 * 10 + h2) * 60 + (m1 * 10 + m2);                                 int diff = Math.floorMod(currTime - original, 24 * 60);                                 if (diff > 0 && diff < minDiff) {                                     ans = currTime;                                     minDiff = diff;                                 }                             }                         }                     }                 }             }         }           return String.format("%02d:%02d", ans / 60, ans % 60);     }           private int getElapsedMinutes(String time) {         int hour = Character.getNumericValue(time.charAt(0)) * 10 + Character.getNumericValue(time.charAt(1));         int min = Character.getNumericValue(time.charAt(3)) * 10 + Character.getNumericValue(time.charAt(4));                   return hour * 60 + min;     } }

Discussion:
One corner case to consider is if the time is 11:11, the next time should be 11:11 as it's for next day. But int the code since we check diff > 0, the ans will return 0. To handle this case, the initial value should be original time.