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：
1 #include<bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 typedef unsigned int uint; 5 typedef unsigned long long ull; 6 typedef pair<int,int> PII; 7 typedef pair<ll,ll> Pll; 8 typedef vector<int> VI; 9 typedef vector<PII> VII; 10 #define N 2100 11 #define M 4100000 12 #define fi first 13 #define se second 14 #define MP make_pair 15 #define pi acos(-1) 16 #define mem(a,b) memset(a,b,sizeof(a)) 17 #define rep(i,a,b) for(int i=(int)a;i<=(int)b;i++) 18 #define per(i,a,b) for(int i=(int)a;i>=(int)b;i--) 19 #define lowbit(x) x&(-x) 20 #define Rand (rand()*(1<<16)+rand()) 21 #define id(x) ((x)<=B?(x):m-n/(x)+1) 22 #define ls p<<1 23 #define rs p<<1|1 24 25 const ll MOD=1e9+7,inv2=(MOD+1)/2; 26 double eps=1e-6; 27 int INF=1e9; 28 int dx[4]={-1,1,0,0}; 29 int dy[4]={0,0,-1,1}; 30 31 int b[N][N],n,m,s; 32 33 int read() 34 { 35 int v=0,f=1; 36 char c=getchar(); 37 while(c<48||57<c) {if(c=='-') f=-1; c=getchar();} 38 while(48<=c&&c<=57) v=(v<<3)+v+v+c-48,c=getchar(); 39 return v*f; 40 } 41 42 int isok(int x,int y) 43 { 44 if(x>=1&&x<=n&&y>=1&&y<=m) return 1; 45 return 0; 46 } 47 48 int drop(int x,int y) 49 { 50 int s1=0,s2=0; 51 if(isok(x-1,y)&&b[x-1][y]==1) s1++; 52 if(isok(x+1,y)&&b[x+1][y]==1) s1++; 53 if(isok(x,y-1)&&b[x][y-1]==1) s2++; 54 if(isok(x,y+1)&&b[x][y+1]==1) s2++; 55 if(s1>0&&s2>0) return 1; 56 return 0; 57 } 58 59 void dfs(int x,int y) 60 { 61 b[x][y]=1; 62 s++; 63 rep(i,0,3) 64 { 65 int tx=x+dx[i],ty=y+dy[i]; 66 if(isok(tx,ty)&&b[tx][ty]==0&&drop(tx,ty)) dfs(tx,ty); 67 } 68 } 69 70 71 int main() 72 { 73 //freopen("1.in","r",stdin); 74 //freopen("1.out","w",stdout); 75 76 int cas; 77 scanf("%d",&cas); 78 79 while(cas--) 80 { 81 n=read(),m=read(); 82 int q=read(); 83 rep(i,1,n) 84 rep(j,1,m) b[i][j]=0; 85 rep(i,1,q) 86 { 87 int x=read(),y=read(); 88 s=0; 89 if(b[x][y]==0) dfs(x,y); 90 printf("%d\n",s); 91 } 92 } 93 94 return 0; 95 }