RT

代码：

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
int n,m,a,b,l,mp[1505][1505],q[10000000005][5],vis[505][505],x,y;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1}; 
signed main(){
	cin>>n>>m>>a>>b;
	for(int i=1;i<=a;i++){
		cin>>x>>y;
		vis[x][y]=1;
		l++;
		q[l][0]=x,q[l][1]=y;
	}
	int x,y,head=l,tail=0;
	while(tail<head){ 
		tail++;
		x=q[tail][0],y=q[tail][1];
		vis[x][y]=1;
		for(int i=0;i<4;i++){
			int x1=x+dx[i],y1=y+dy[i];
			if(x1<1||y1<1||x1>n||y1>m||vis[x1][y1]) continue;
			vis[x1][y1]=1,mp[x1][y1]=mp[x][y]+1,q[++head][0]=x1,q[head][1]=y1;
		}
	}
	for(int i=1;i<=b;i++){
		cin>>x>>y;
		cout<<mp[x][y]<<endl;
	}
	return 0;
}

求大佬、巨佬