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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main()
{
	int check(int,int,int,int) ,c, n[4];
	scanf("%d %d %d %d",&n[0], &n[1], &n[2], &n[3]);
	
	if(n[0]!=1 && n[0]!=7 && n[0]!=9 && n[0]!= 4){
		c = 0;
	}else if((n[1]!=1 && n[1]!=7 && n[1]!=9 && n[1]!= 4)||(n[0]==n[1])){
		c = 0;
	}else if((n[2]!=1 && n[2]!=7 && n[2]!=9 && n[2]!= 4)||(n[2]==n[1])||(n[2]==n[0])){
		c = 0;
	}else if((n[3]!=1 && n[3]!=7 && n[3]!=9 && n[3]!= 4)||(n[3]==n[1])||(n[3]==n[0])||(n[3]==n[2])){
		c = 0;
	}else c = 1;
	
	if(c==1) printf("YES");
	else printf("NO");
}