Find them, Catch them -种类并查

• Find them, Catch them

•  POJ - 1703 

• #include<stdio.h>
  #include<cstring>
  using namespace std;
  #define maxn 2222
  int n,m,x,y,T;
  struct node
  {
      int pos,same;
  } xre,yre;
  int fa[maxn*1000];
  bool ans[maxn];
  char str;
  node fond(int x)
  {
      node ret;
      if(fa[x]==0)
      {
          ret.pos=x;
          ret.same=true;
          return ret;
      }
      if(fa[x]>0)
      {
          ret=fond(fa[x]);
          if(ret.same)fa[x]=ret.pos;
          else
              fa[x]=-ret.pos;
          return ret;
      }
      ret=fond(-fa[x]);
      if(ret.same)fa[x]=-ret.pos;
      else fa[x]=ret.pos;
      ret.same=!ret.same;
      return ret;
  }
  int main()
  {
      scanf("%d",&T);
      for(int t=1; t<=T; t++)
      {
          scanf("%d%d",&n,&m);
          for(int i=1; i<=n; i++)
              fa[i]=0;
          while(m--)
          {
              getchar();
              scanf("%c",&str);
              scanf("%d%d",&x,&y);
              if(str=='D')
              {
                  xre=fond(x);
                  yre=fond(y);
                  if(xre.pos!=yre.pos)
                  {
                      if(xre.same==yre.same)
                          fa[xre.pos]=-yre.pos;
                      else
                          fa[xre.pos]=yre.pos;
                  }
              }
              if(str=='A')
              {
                  xre=fond(x);
                  yre=fond(y);
                  if(xre.pos!=yre.pos)
                      printf("Not sure yet.\n");
                  else
                  {
                      if(xre.same==yre.same)
                          printf("In the same gang.\n");
                      else
                          printf("In different gangs.\n");
                  }
              }
          }
      }
      return 0;
  }
  

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