949. 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: [,,,]
Output: "23:41"

Example 2:

Input: [,,,]
Output: ""

Note:

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

过滤掉不匹配的时间，然后更新最大时间即可。

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

class Solution
{
    public:
        string largestTimeFromDigits(vector<int>& a)
        {
            vector<,-);
            sort(a.begin(),a.end());
            do
            {
                ]>)
                    continue;
                ]*+a[]>=)
                    continue;
                ]*+a[]>=)
                    continue;

                ]>b[]||a[]>b[]||a[]>b[]||a[]>b[])
                    ;i<;++i)
                        b[i]=a[i];
            }while(next_permutation(a.begin(),a.end()));
            ]==-)
                return "";
            ])+to_string(b[])+])+to_string(b[]);
        }
};
int main()
{
    Solution s;
    ]={,,,};
    vector<);
    cout<<s.largestTimeFromDigits(t)<<endl;
    ;
}