POJ - 2236 Wireless Network （并查集）

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <algorithm>
#include <cmath>
#include <ctime>
#include <vector>
#include <queue>
#include <map>
#include <stack>
#include <set>
#include <bitset>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define ms(a, b) memset(a, b, sizeof(a))
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define eps 0.0000000001
#define IOS ios::sync_with_stdio(0);cin.tie(0);
#define random(a, b) rand()*rand()%(b-a+1)+a
#define pi acos(-1)
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const int inf = 0x3f3f3f3f;
const int maxn = 1000 + 100;
const int maxm = 200000 + 10;
const int mod = 998244353;
int fa[maxn];
int n,d;
pair<int,int> p[maxn];
bool check(pair<int,int> x,pair<int,int> y){
    return (x.first-y.first)*(x.first-y.first)+(x.second-y.second)*(x.second-y.second)<=d*d;
}
int find(int x){
    return x==fa[x]?x:fa[x]=find(fa[x]);
}
void Union(int x,int y){
    int fx=find(x),fy=find(y);
    if(fx!=fy) fa[fx]=fy;
}
int tmp[maxn];
int main() {
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
#endif
    scanf("%d%d",&n,&d);
    for(int i=1;i<=n;i++) scanf("%d%d",&p[i].first,&p[i].second),fa[i]=i;

    char op[3];
    int x,y;
    int cnt=0;
    while(~scanf("%s",op)){
        if(op[0]==‘O‘){
            scanf("%d",&x);
            for(int i=0;i<cnt;i++){
                if(tmp[i]!=x&&check(p[tmp[i]],p[x])){
                    Union(tmp[i],x);
                }
            }
            tmp[cnt++]=x;
        }else{
            scanf("%d%d",&x,&y);
            int fx=find(x),fy=find(y);
            if(fx!=fy) puts("FAIL");
            else puts("SUCCESS");
        }
    }
    return 0;
}