poj 2485 Highways

一道简单的最小生成树问题；

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<queue>
#include<map>
#include<cstring>
#include<vector>
using namespace std;
class Kru
{
public:
      int x,y,dis;
}kru[250024];
int set[524];
bool cmp(Kru a , Kru b )
{
    return a.dis < b.dis;    
}
int find( int x )
{
   return set[x] == x ? x : set[x] = find( set[x] );    
}
int Kruscal( int N )
{
  int ans,X,Y;
  for( int i = 0 ; i < N ; i++ )
  {
     if( ( X = find( kru[i].x ) )!=( Y = find(kru[i].y) ) )
     {
         ans = kru[i].dis;
         set[Y] =X;        
     }
  }    
  return ans;
}
int main(  )
{
     int N,Case,dis;
     while( scanf( "%d",&Case )==1 )
     {
         while( Case -- )
         {
             int count = 0 ;
             scanf( "%d",&N );
             for( int i = 1 ; i <= N ; i++ )
             {
                set[i] = i;
                for( int j = 1 ; j <= N; j ++ )
                {
                     scanf( "%d",&dis );
                     kru[count].x = i;kru[count].y=j;
                     kru[count++].dis = dis;    
                }    
             }
             sort( kru ,kru + count , cmp );
             printf( "%d\n",Kruscal( count ) );        
         }        
     }
    //system( "pause" );
    return 0;
}