洛谷P1789【Mc生存】插火把 题解

题目传送门

这道题目可以纯暴力：

#include<bits/stdc++.h>
//Minecraft 666
using namespace std;
int a[][];
int n,m,k,ans;
int main(){
    scanf("%d%d%d",&n,&m,&k);
    for(int i=;i<=m;i++){
        int x,y;
        scanf("%d%d",&x,&y);
        a[x-][y]=;a[x-][y]=;a[x][y]=;a[x+][y]=;a[x-][y-]=;a[x+][y-]=;
        a[x+][y]=;a[x][y+]=;a[x][y+]=;a[x][y-]=;a[x][y-]=;a[x+][y+]=;a[x-][y+]=;
    }
    for(int i=;i<=k;i++){
        int x,y;
        scanf("%d%d",&x,&y);
        a[x-][y-]=;a[x-][y-]=;a[x][y-]=;a[x+][y-]=;a[x+][y-]=;
        a[x-][y-]=;a[x-][y-]=;a[x][y-]=;a[x+][y-]=;a[x+][y-]=;
        a[x-][y]=;a[x-][y]=;a[x][y]=;a[x+][y]=;a[x+][y]=;
        a[x-][y+]=;a[x-][y+]=;a[x][y+]=;a[x+][y+]=;a[x+][y+]=;
        a[x-][y+]=;a[x-][y+]=;a[x][y+]=;a[x+][y+]=;a[x+][y+]=;
    }
    for(int i=;i<=n;i++)
        for(int j=;j<=n;j++)
            if(a[i][j]==) ans++;
    printf("%d\n",ans);
    return ;
}