为什么只有我写了六十多行

比较暴力...

#include<iostream>
#include<cstdio>
#include<bits/stdc++.h>
using namespace std;
int a[10050][10050],x,y,n,i,j,m,k,sum=0;
int main(){
	cin>>n;
	for(i=1;i<=n;i++){
		for(j=1;j<=n;j++){
			a[i][j]=0;
		}
	}
	cin>>m>>k;
	for(i=1;i<=m;i++){
		cin>>x>>y;
		a[x][y]=1;
		a[x+1][y]=1;
		a[x+2][y]=1;
		a[x-1][y]=1;
		a[x-2][y]=1;
		a[x][y+1]=1;
		a[x][y+2]=1;
		a[x][y-1]=1;
		a[x][y-2]=1;
		a[x-1][y+1]=1;
		a[x+1][y+1]=1;
		a[x-1][y-1]=1;
		a[x+1][y-1]=1;
	}
	for(i=1;i<=k;i++){
		a[x][y]=1;
		a[x+1][y]=1;
		a[x+2][y]=1;
		a[x-1][y]=1;
		a[x-2][y]=1;
		a[x][y+1]=1;
		a[x][y+2]=1;
		a[x][y-1]=1;
		a[x][y-2]=1;
		a[x-1][y+1]=1;
		a[x+1][y+1]=1;
		a[x-1][y-1]=1;
		a[x+1][y+1]=1;
		a[x+2][y+1]=1;
		a[x-2][y+1]=1;
		a[x-2][y+2]=1;
		a[x+2][y+2]=1;
		a[x+2][y-1]=1;
		a[x-2][y-1]=1;
		a[x-2][y-2]=1;
		a[x+2][y-2]=1;
		a[x+1][y-2]=1;
		a[x-1][y-2]=1;
		a[x+1][y+2]=1;
		a[x-1][y+2]=1;
	}
	for(i=1;i<=n;i++){
		for(j=1;j<=n;j++){
			if(a[i][j]==0){
			   sum++;	
			}
		}
	}
	cout<<sum;
	return 0;
}

本蒟蒻感觉没错...