同一份代码

#include <queue>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

const int maxn = 5e2 + 10, dx[] = {1, -1}, dy[] = {0, 0, 1, -1};
queue<int> qx, qy;
bool vis[maxn][maxn];
int n, m, a, b, tx, ty, nx, ny, dis[maxn][maxn];
int main() {
	scanf("%d %d %d %d", &n, &m, &a, &b);
	while (a--) {
		scanf("%d %d", &tx, &ty);
		vis[tx][ty] = true;
		qx.push(tx), qy.push(ty);
	}
	while (qx.size()) {
		tx = qx.front();
		ty = qy.front();
		for (int i = 0; i <= 3; i++) {
			nx = tx + dx[i];
			ny = ty + dy[i];
			if (nx < 1 || nx > n || ny < 1 || ny > m || vis[nx][ny]) continue;
			vis[nx][ny] = true;
			qx.push(nx), qy.push(ny);
			dis[nx][ny] = dis[tx][ty] + 1;
		}
		qx.pop();
		qy.pop();
	}
	while (b--) {
		scanf("%d %d", &tx, &ty);
		printf("%d\n", dis[tx][ty]);
	}
	return 0;
}

使用C++98/C++98 O2/C++14(GCC9) O2交就全WA，下载数据.out的是个这玩意：ਰ਱ਰ਱ਰਰਰਲ਱਱ਰ਱਱ਲ਱ਰਰ਱ਰ਱ਰਰ਱ਰਰ਱਱ਰ਱ਰਰਰ਱ਰਰਰਰਰ਱਱ਰਰਰ਱਱ਰ਱਱ਰਰ

什么玩意啊