Largest Time for Given Digits

Given 4 digits (0-9), arrange them to form the largest valid time in HH:MM format. If no valid time can be formed, return empty string.

Examples
Input: [1,2,3,4]
Output: "23:41"
Hints

Largest Time for Given Digits

Given 4 digits (0-9), arrange them to form the largest valid time in HH:MM format. If no valid time can be formed, return empty string.