nyoj 1058部分和问题

#include <stdio.h>
int n, k, ok, arr[22], vis[22], count;
 
void DFS(int pos){
    if(count >= k)
	{
        if(count == k)
		{
            if(!ok){
                ok = 1; printf("YES\n");
            }
            for(int i = 0; i < n; ++i)
                if(vis[i]) printf("%d ", arr[i]);
            printf("\n");
        }
        return;
    }
     
    for(int i = pos; i < n; ++i){
        count += arr[i];
        vis[i] = 1;
        DFS(i + 1);
        count -= arr[i];
        vis[i] = 0;
    }
}
 
int main(){
    while(scanf("%d%d", &n, &k) == 2){
        ok = 0;
        for(int i = 0; i < n; ++i){
            scanf("%d", arr + i);
            vis[i] = 0;
        }
        count = 0; DFS(0);
        if(!ok) printf("NO\n");
    }
    return 0;
}