POJ 2236(并查集裸）

POJ2236

#include <iostream>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <string>
#include <map>
#include <iomanip>
#include <algorithm>
#include <queue>
#include <stack>
#include <set>
#include <vector>
//const int maxn = 1e5+5;
#define ll long long
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

#define MAX INT_MAX
#define FOR(i,a,b) for( int i = a;i <= b;++i)
#define bug cout<<"--------------"<<endl
using namespace std;
struct node
{
    int x,y;
}v[1100];
int d,n;
int dp[1100][1100];
int vis[1100],pre[1100];
int dis(int a,int b)
{
    double temp=(v[a].x-v[b].x)*(v[a].x-v[b].x)+(v[a].y-v[b].y)*(v[a].y-v[b].y);
    temp=sqrt(temp);
    if(temp<=d) return 1;
    return 0;
}
int Find(int x)
{
    if(pre[x]!=x) return Find(pre[x]);
    return  x;
}
void  howhead(int x,int y)
{
    int headx=Find(x);
    int heady=Find(y);
    if(headx!=heady)
    {
        pre[headx]=heady;
    }
}
int main()
{
//   freopen("C:\Users\方瑞\Desktop\input.txt","r",stdin);
//    freopen("C:\Users\方瑞\Desktop\output.txt","w",stdout);
    cin>>n>>d;
    FOR(i,1,n)
    {
        cin>>v[i].x>>v[i].y;
    }
    FOR(i,1,n)
    {
        FOR(j,i,n)
        {
            if(dis(i,j))
            {
                dp[i][j]=1;
                dp[j][i]=1;
            }
        }
    }
    FOR(i,1,n) pre[i]=i;
    char c;
    while(cin>>c)
    {
        if(c=='O')
        {
            int hhh ;
            cin>>hhh;
            vis[hhh]=1;   //注意这个位置================================
            for(int i=1;i<=n;++i)
            {
                if(vis[i]==1 && dp[hhh][i]==1)
                {
                    howhead(i,hhh);

                }
            }
        }
        else
        {
            int a,b;
            cin>>a>>b;

            if(Find(a)==Find(b))
                cout<<"SUCCESS"<<endl;
            else cout<<"FAIL"<<endl;
        }
    }

}