hdu1198 Farm Irrigation 并查集

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1198

简单并查集

分别合并竖直方向和水平方向即可

代码：

 #include<iostream>
 #include<cstdlib>
 #include<cstdio>
 #include<cstring>
 #define maxn 110
 using namespace std;
 int parent[maxn*maxn];
 char map[maxn][maxn];
 int find(int x)
 {
    int s;
    for(s=x;parent[s]>=;s=parent[s]);
    while(s!=x)
    {
       int tmp=parent[x];
       parent[x]=s;
       x=tmp;
    }
    return s;
 }
 void Union(int r1,int r2)
 {
      int R1=find(r1);
      int R2=find(r2);
      int tmp=parent[R1]+parent[R2];
      if(parent[R1]>parent[R2])
      {
           parent[R1]=R2;
           parent[R2]=tmp;
      }
      else
      {
          parent[R2]=R1;
          parent[R1]=tmp;
      }
 }
 int main()
 {
     int  m,n;
     while(scanf("%d%d",&m,&n)!=EOF)
     {
         if(m< || n<) break;
         for(int i=;i<m;i++)
          scanf("%s",map[i]);
         for(int i=;i<m*n;i++)
         parent[i]=-;
         for(int i=;i<m;i++)
          for(int j=;j<n;j++)
          {
             if(i> && (map[i][j]=='A' ||map[i][j]=='B'||map[i][j]=='E'||map[i][j]=='G'||map[i][j]=='H'||map[i][j]=='J'||map[i][j]=='K'))
             if(map[i-][j]=='C'||map[i-][j]=='D'||map[i-][j]=='E'||map[i-][j]=='H'||map[i-][j]=='I'||map[i-][j]=='J'||map[i-][j]=='K')
             Union(i*n+j,(i-)*n+j);
             if(j>&&(map[i][j]=='A'||map[i][j]=='C'||map[i][j]=='F'||map[i][j]=='G'||map[i][j]=='H'||map[i][j]=='I'||map[i][j]=='K'))
             if(map[i][j-]=='B'||map[i][j-]=='D'||map[i][j-]=='F'||map[i][j-]=='G'||map[i][j-]=='I'||map[i][j-]=='J'||map[i][j-]=='K')
             Union(i*n+j,i*n+j-);
 
         }
         int ans=;
         for(int i=;i<m*n;i++)
         if(parent[i]<) ans++;
         cout<<ans<<endl;
     }
 return ;
 }