poj1703

简单并查集

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      #include 
    
      <
    
      iostream
    
      >
    
      
#include 
    
      <
    
      cstdio
    
      >
    
      
#include 
    
      <
    
      cstdlib
    
      >
    
      
#include 
    
      <
    
      cstring
    
      >
    
      

    
      using
    
       
    
      namespace
    
       std;


    
      #define
    
       maxn 100005
    
      


    
      int
    
       n, m;

    
      int
    
       f[maxn], father[maxn];


    
      int
    
       getanc(
    
      int
    
       a)
{
 
    
      if
    
       (a 
    
      ==
    
       father[a])
 
    
      return
    
       a;
 
    
      return
    
       father[a] 
    
      =
    
       getanc(father[a]);
}


    
      void
    
       merge(
    
      int
    
       a, 
    
      int
    
       b)
{
 father[getanc(a)] 
    
      =
    
       getanc(b);
}


    
      void
    
       differ(
    
      int
    
       a, 
    
      int
    
       b)
{
 
    
      if
    
       (f[a] 
    
      ==
    
       
    
      -
    
      1
    
      )
 f[a] 
    
      =
    
       b;
 
    
      else
    
      
 merge(f[a], b);
 
    
      if
    
       (f[b] 
    
      ==
    
       
    
      -
    
      1
    
      )
 f[b] 
    
      =
    
       a;
 
    
      else
    
      
 merge(f[b], a);
}


    
      void
    
       ask(
    
      int
    
       a, 
    
      int
    
       b)
{
 
    
      if
    
       (f[a] 
    
      ==
    
       
    
      -
    
      1
    
       
    
      ||
    
       f[b] 
    
      ==
    
       
    
      -
    
      1
    
      )
 {
 printf(
    
      "
    
      Not sure yet.\n
    
      "
    
      );
 
    
      return
    
      ;
 }
 
    
      if
    
       (getanc(a) 
    
      ==
    
       getanc(b))
 {
 printf(
    
      "
    
      In the same gang.\n
    
      "
    
      );
 
    
      return
    
      ;
 }
 
    
      if
    
       (getanc(a) 
    
      ==
    
       getanc(f[b]))
 {
 printf(
    
      "
    
      In different gangs.\n
    
      "
    
      );
 
    
      return
    
      ;
 }
 printf(
    
      "
    
      Not sure yet.\n
    
      "
    
      );
}


    
      int
    
       main()
{
 
    
      //
    
      freopen("t.txt", "r", stdin);
    
      

    
       
    
      int
    
       t;
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      t);
 
    
      while
    
       (t
    
      --
    
      )
 {
 memset(f, 
    
      -
    
      1
    
      , 
    
      sizeof
    
      (f));
 scanf(
    
      "
    
      %d%d
    
      "
    
      , 
    
      &
    
      n, 
    
      &
    
      m);
 getchar();
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       n; i
    
      ++
    
      )
 father[i] 
    
      =
    
       i;
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       m; i
    
      ++
    
      )
 {
 
    
      char
    
       ch;
 
    
      int
    
       a, b;
 scanf(
    
      "
    
      %c%d%d
    
      "
    
      , 
    
      &
    
      ch, 
    
      &
    
      a, 
    
      &
    
      b);
 a
    
      --
    
      ;
 b
    
      --
    
      ;
 getchar();
 
    
      if
    
       (ch 
    
      ==
    
       
    
      '
    
      D
    
      '
    
      )
 differ(a, b);
 
    
      else
    
      
 ask(a, b);
 }
 }
 
    
      return
    
       
    
      0
    
      ;
}