请大佬帮忙看看

#include <iostream>
using namespace std;

const int N = 1001;
const short dx[4] = {1, 0, -1, 0};
const short dy[4] = {0, 1, 0, -1};
bool map[N][N], vis[N][N];
short n;
int m;

void dfs(short x, short y){
	if(x <= 0 || x > n || y <= 0 || y > n || vis[x][y]){
		return ;
	}
	bool flag = map[x][y];
	vis[x][y] = true;
	for(int i=0; i<4; i++)
		if(map[x+dx[i]][y+dy[i]] == (!flag))
			dfs(x + dx[i], y + dy[i]);
}

int found(){
	int ans=0;
	for(int i=1; i<=n; i++)
		for(int j=1; j<=n; j++)
			if(vis[i][j])
				ans++;
	return ans;
}

void cl(){
	for(int i=1; i<=n; i++)
		for(int j=1; j<=n; j++)
			vis[i][j] = false;
}

int main(){
	cin >> n >> m;
	for(int i=1; i<=n; i++)
		for(int j=1; j<=n; j++)
			cin >> map[i][j];
	for(int i=0; i<m; i++){
		short x, y;
		cin >> x >> y;
		dfs(x, y);
		int ans = found();
		cout << ans << endl;
		cl();
	}
	return 0;
}