113th LeetCode Weekly Contest Largest Time for Given Digits

Given an array of 4 digits, return the largest 24 hour time that can be made.

The smallest 24 hour time is 00:00, and the largest is 23:59.  Starting from 00:00, a time is larger if more time has elapsed since midnight.

Return the answer as a string of length 5.  If no valid time can be made, return an empty string.

Example 1:

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

Example 2:

Input: [5,5,5,5]
Output: ""

Note:

1. A.length == 4
2. 0 <= A[i] <= 9

给四个数字，组合成时间看得到的最大值是多少

全排列过去，把不符合规定的筛选掉就OK

class Solution {
public:
    string largestTimeFromDigits(vector<int>& A) {
        int x[];
        for(int i=;i<;i++){
            x[i]=A[i];
        }
        string u = "";
        sort(x,x+);
        do{
            if(x[]>=){
            continue;
            }
            if(x[]==){
                if(x[]>){
                    continue;
                }
            }
            if(x[]>=){
                continue;
            }

            int H,M;
            u = "";
            u += to_string(x[]);
            u += to_string(x[]);
            u +=':';
            u += to_string(x[]);
            u += to_string(x[]);
            cout<<u<<endl;
            cout<<x[]<<" "<<x[]<<" "<<x[]<<" "<<x[]<<endl;
        }while(next_permutation(x,x+));
        return u;
    }
};