模拟水题，查看二维数组是否有一列都为1(POJ2864)

#include <cstdio>
#include <cstdlib>
#include <cstring>

int arr[510][110];

int main(void) {
    int r, c;
    int i, j;
    int flag;

    while(scanf("%d%d", &c, &r), c != 0 || r != 0) {
        memset(arr, 0, sizeof(arr));
        for (i = 0; i < r; i++) {
            for (j = 0; j < c; j++) {
                scanf("%d", &arr[i][j]);
            }
        }
        for (j = 0; j < c; j++) {
            flag = 0;
            for (i = 0; i < r; i++) {
                if (arr[i][j] == 1) {
                    flag++;
                }
            }
            if (flag == r) {
                break;
            }
        }
        if (flag == r) {
            printf("yes\n");
        } else {
            printf("no\n");
        }
    }
    return 0;
}