DFS 和 BFS 都试过了，都是70，7 AC 3 TLE 。 DFS

#include<bits/stdc++.h>
using namespace std;
#define N 1010
bool mp[N][N], vis[N][N];
int ans, n, m, xx, yy;
int dx[4] = {-1, 0, 0, 1};
int dy[4] = {0, -1, 1, 0};
void dfs(int x, int y) {
	ans++;
	vis[x][y] = 1;
	for (int i = 0; i < 4; i++) {
		int sx = x + dx[i], sy = y + dy[i];
		if (mp[sx][sy] == !mp[x][y] && sx >= 1 && sx <= n && sy >= 1 && sy <= n && !vis[sx][sy]) dfs(sx, sy);
	}
}
int main() {
	cin >> n >> m;
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) {
		char c;
		cin >> c;
		mp[i][j] = c - '0';
	}
	for (int i = 1; i <= m; i++) {
		memset(vis, 0, sizeof(vis));
		ans = 0;
		cin >> xx >> yy;
		dfs(xx, yy);
		cout << ans << endl;
	}
	return 0;
}

BFS

#include<bits/stdc++.h>
using namespace std;
#define N 1010
bool mp[N][N], vis[N][N];
int ans, n, m, xx, yy;
int dx[4] = {-1, 0, 0, 1};
int dy[4] = {0, -1, 1, 0};
struct node {
	int x, y;
};
queue<node> q;
void bfs() {
	q.push(node{xx, yy});
	vis[xx][yy] = true;
	while (!q.empty()) {
		node tmp = q.front();
		int x = tmp.x, y = tmp.y;
		ans++;
		for (int i = 0; i < 4; i++) {
			int sx = x + dx[i], sy = y + dy[i];
			if (mp[sx][sy] == !mp[x][y] && sx >= 1 && sx <= n && sy >= 1 && sy <= n && !vis[sx][sy]) {
				vis[sx][sy] = true;
				q.push(node{sx, sy});
			}
		}
		q.pop();
	}
} 
int main() {
	cin >> n >> m;
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) {
		char c;
		cin >> c;
		mp[i][j] = c - '0';
	}
	for (int i = 1; i <= m; i++) {
		memset(vis, 0, sizeof(vis));
		ans = 0;
		cin >> xx >> yy;
		bfs();
		cout << ans << endl;
	}
	return 0;
}