【HDOJ6699】Block Breaker（模拟）

题意：给定一个n*m的网格块，如果一个块水平或垂直方向没有相邻支撑就会掉下去

有q次询问，每次会掉下去一块，问连锁反应新掉下的块数

n，m<=2e3，q<=1e5

思路：

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 typedef unsigned int uint;
 typedef unsigned long long ull;
 typedef pair<int,int> PII;
 typedef pair<ll,ll> Pll;
 typedef vector<int> VI;
 typedef vector<PII> VII;
 #define N  2100
 #define M  4100000
 #define fi first
 #define se second
 #define MP make_pair
 #define pi acos(-1)
 #define mem(a,b) memset(a,b,sizeof(a))
 #define rep(i,a,b) for(int i=(int)a;i<=(int)b;i++)
 #define per(i,a,b) for(int i=(int)a;i>=(int)b;i--)
 #define lowbit(x) x&(-x)
 #define Rand (rand()*(1<<16)+rand())
 #define id(x) ((x)<=B?(x):m-n/(x)+1)
 #define ls p<<1
 #define rs p<<1|1

 const ll MOD=1e9+,inv2=(MOD+)/;
       double eps=1e-;
       int INF=1e9;
       int dx[]={-,,,};
       int dy[]={,,-,};

 int b[N][N],n,m,s;

 int read()
 {
    int v=,f=;
    char c=getchar();
    while(c<||<c) {if(c=='-') f=-; c=getchar();}
    while(<=c&&c<=) v=(v<<)+v+v+c-,c=getchar();
    return v*f;
 }

 int isok(int x,int y)
 {
     if(x>=&&x<=n&&y>=&&y<=m) return ;
     return ;
 }

 int drop(int x,int y)
 {
     int s1=,s2=;
     if(isok(x-,y)&&b[x-][y]==) s1++;
     if(isok(x+,y)&&b[x+][y]==) s1++;
     if(isok(x,y-)&&b[x][y-]==) s2++;
     if(isok(x,y+)&&b[x][y+]==) s2++;
     if(s1>&&s2>) return ;
     return ;
 }

 void dfs(int x,int y)
 {
     b[x][y]=;
     s++;
     rep(i,,)
     {
         int tx=x+dx[i],ty=y+dy[i];
         if(isok(tx,ty)&&b[tx][ty]==&&drop(tx,ty)) dfs(tx,ty);
     }
 }

 int main()
 {
     //freopen("1.in","r",stdin);
     //freopen("1.out","w",stdout);

     int cas;
     scanf("%d",&cas);

     while(cas--)
     {
         n=read(),m=read();
         int q=read();
         rep(i,,n)
          rep(j,,m) b[i][j]=;
         rep(i,,q)
         {
             int x=read(),y=read();
             s=;
             if(b[x][y]==) dfs(x,y);
             printf("%d\n",s);
         }
     }

     return ;
 }