（zoj 2412 Farm Irrigation）<SB并查集>

Solution

Code

// by spli
#include<cstring>
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;

const int N=55;
int n,m;
int f[N*N];
char s[60][60];

int _find(int x){
if(x!=f[x]) f[x]=_find(f[x]);
return f[x];
}

void un(int x,int y){
if(x<=0||y<=0) return;
if(x>n*m||y>n*m) return;
//cout<<x<<" "<<y<<endl;
int r1=_find(x);
int r2=_find(y);
if(r1!=r2) f[r1]=r2;
}

int main(){
while(scanf("%d%d",&n,&m)&&n!=-1){
for(int i=1;i<=n*m;++i) f[i]=i;
for(int i=1;i<=n;++i)
scanf("%s",s[i]+1);
for(int i=1;i<=n;++i){
for(int j=1;j<=m;++j){
if(s[i][j]=='A'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
}
if(s[i][j]=='B'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
}
if(s[i][j]=='C'){
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
if(s[i][j]=='D'){
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
if(s[i][j]=='E'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
if(s[i][j]=='F'){
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
}
if(s[i][j]=='G'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
}
if(s[i][j]=='H'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
if(s[i][j]=='I'){
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
}
if(s[i][j]=='J'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
if(s[i][j]=='K'){
if(s[i-1][j]!='B'&&s[i-1][j]!='F'&&s[i-1][j]!='G'&&s[i-1][j]!='A') un((i-2)*m+j,(i-1)*m+j);
if(s[i][j-1]!='A'&&s[i][j-1]!='C'&&s[i][j-1]!='E'&&s[i][j-1]!='H'&&j!=1) un((i-1)*m+j-1,(i-1)*m+j);
if(s[i][j+1]!='B'&&s[i][j+1]!='D'&&s[i][j+1]!='E'&&s[i][j+1]!='J'&&j!=m) un((i-1)*m+j+1,(i-1)*m+j);
if(s[i+1][j]!='C'&&s[i+1][j]!='D'&&s[i+1][j]!='F'&&s[i+1][j]!='I') un(i*m+j,(i-1)*m+j);
}
}
}
int ans=0;
for(int i=1;i<=n*m;++i)
if(_find(i)==i) ans++;
printf("%d\n",ans);
}
return 0;
}