杭电ACM1096，一直有错误，求帮忙

我的代码
#include

int main(){

int n, i;
int a, b;
int x, sum;

while(scanf("%d", &n) != EOF){

    for (i = 0; i < n; i++){

        scanf("%d", &a);

        for (b = 0; b < a; b++){

            sum = 0;
            scanf("%d", &x);

            sum = sum + x;
            printf("%d", sum);
            printf("\n");
        }

    }

}

return 0;

}