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: Wrong Answer)

#include<stdio.h>
int main()
{
  int n1,n2,n3,n4,w=0,x=0,y=0,z=0;
  scanf("%d %d %d %d",&n1,&n2,&n3,&n4);
  if(n1==1 || n2==1 || n3==1 || n4==1)
    w++;
  if(n1==9 || n2==9 || n3==9 || n4==9)
   x++;
  if(n1==7|| n2==7 || n3==7 || n4==7)
    y++;
  if(n1==4 || n2==4 || n3==4 || n4==4)
    z++;
  if(x==0 && y==0 && w==0 && z==0)
    printf("YES");
  else
    printf("NO");
}