HDU 4496 D-City

并查集倒过来用就好了，水题。

但是题目貌似有多组数据，可又没有说明，导致我wa了两次。

#include<stdio.h>
#include<iostream>
using namespace std;

#include<math.h>
#include<algorithm>
#include<string.h>
#include<stdlib.h>
#include<vector>
#include<set>
#include<map>
#include<stack>
#include<string>
#include<queue>

#define repA(p,q,i)  for( int (i)=(p); (i)!=(q); ++(i) )
#define repAE(p,q,i)  for( int (i)=(p); (i)<=(q); ++(i) )
#define repD(p,q,i)  for( int (i)=(p); (i)!=(q); --(i) )
#define repDE(p,q,i)  for( int (i)=(p); (i)>=(q); --(i) )
#define range 100010

int n,m;
int road[range][2]; 
int f[range];
int condition[range];

int find(int s);

int main()
{
    
    while( scanf("%d%d",&n,&m) != EOF )
    {
    repAE(1,m,i)
      scanf("%d%d",&road[i][0], &road[i][1]);

    repA(0,n,i)  f[i] = i;
    
    int all=n;
    condition[m] = n;
    int p,q;

    repDE(m,1,i)
    {
        p = find(road[i][0] ) ;
        q = find(road[i][1] ) ;

        if(p != q)
        {
            f[q] = p;
              --all;
        }

        condition[i-1]=all;
    }

    repAE(1,m,i)
      printf("%d\n",condition[i]);
    }
    //while(1);
    return 0;
}

int find( int s )
{
    if( s != f[s] )
      f[s] = find( f[s] );
    return f[s];    
}