这是本蒟蒻的代码

#include<bits/stdc++.h>
using namespace std;
int n,m,k,x,y,a[101][101],s;
int main()
{
	cin>>n>>m>>k;
	for(int i=1 ;i<=m;i++)
	{
		cin>>x>>y;
		a[x][y]=a[x][y+2]=a[x-1][y+1]=a[x][y+1]=a[x+1][y+1]=a[x-2][y]=a[x-1][y]=a[x+1][y]=a[x+2][y]=a[x-1][y-1]=a[x][y-1]=a[x+1][y-1]=a[x][y-2]=1;
	}
	for(int i=1;i<=k;i++)
	{
		cin>>x>>y;
		a[x][y]=a[x][y+2]=a[x-1][y+1]=a[x][y+1]=a[x+1][y+1]=a[x-2][y]=a[x-1][y]=a[x+1][y]=a[x+2][y]=a[x-1][y-1]=a[x][y-1]=a[x+1][y-1]=a[x][y-2]=a[x-2][y-2]=a[x-1][y-2]=a[x+1][y-2]=a[x+2][y-2]=a[x+2][y-1]=a[x+2][y+1]=a[x-2][y+1]=a[x+2][y+2]=a[x+1][y+2]=a[x-1][y+2]=a[x-2][y+2];
	}
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
			if(a[i][j]==0)
				s++;
	cout<<s;
	return 0;
}