Problem:
Score : 100 points

Problem Statement

You are given four digits N_1, N_2, N_3 and N_4. Determine if these can be arranged into the sequence of digits "1974".

Constraints

0 \leq N_1, N_2, N_3, N_4 \leq 9

N_1, N_2, N_3 and N_4 are integers.

Input

Input is given from Standard Input in the following format:

N_1 N_2 N_3 N_4

Output

If N_1, N_2, N_3 and N_4 can be arranged into the sequence of digits "1974", print YES; if they cannot, print NO.

Sample Input 1

1 7 9 4

Sample Output 1

YES

We can get 1974 by swapping N_2 and N_3.

Sample Input 2

1 9 7 4

Sample Output 2

YES

We already have 1974 before doing anything.

Sample Input 3

1 2 9 1

Sample Output 3

NO

Sample Input 4

4 9 0 8

Sample Output 4

NO

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int sum = 0;
    vector<int> A(4);
    for (int i = 0; i < 4; i++)
    {
        cin >> A[i];
    }
    for (int i = 0; i < 4; i++)
    {
        if (A[i] == 1 || A[i] == 9 || A[i] == 7 || A[i] == 4)
        {
            sum++;
        }
    }
    if (sum == 4)
    {
        cout << "YES" << endl;
    }
    else
    {
        cout << "NO" << endl;
    }
}