记录

#include<bits/stdc++.h>
using namespace std;

struct pos{
	int x,y;
};

int n,m;
int mp[1145][1145],dx[]={0,0,1,0,-1},dy[]={0,-1,0,1,0};
bool vis[1145][1145];
queue<pos> bq; 

int bfs(int sx,int sy){
	int cnt=0;
	pos start; start.x=sx; start.y=sy;
	while(!bq.empty()) bq.pop();
	memset(vis,0,sizeof(vis));
	bq.push(start);
	while(!bq.empty()){
		pos now=bq.front();
		bq.pop();
		cnt++;
		vis[now.x][now.y]=true;
		for(int i=1;i<=4;i++){
			pos will;
			will.x=now.x+dx[i]; will.y=now.y+dy[i];
			if(will.x<1||will.x>n||will.y<1||will.y>n) continue;
			if(vis[will.x][will.y]) continue;
			if(mp[will.x][will.y]==mp[now.x][now.y]) continue;
			bq.push(will);
			vis[will.x][will.y]=true;
		}
	}
	return cnt;
}

int main(){
    ios::sync_with_stdio(false);
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			char tmp;
			cin>>tmp;
			mp[i][j]=tmp-'0';
		}
	}
	for(int i=1;i<=m;i++){
		int sx,sy;
		cin>>sx>>sy;
		cout<<bfs(sx,sy)<<endl;;
	}
	return 0;
}