POJ 2236 Wireless Network（并查集）

来源：互联网发布：西成高铁知乎编辑：程序博客网时间：2024/05/16 00:39

简单的并查集，不过真佩服那些几十毫秒AC的。我用了1000ms+

#include <cstdio>#include <cstdlib>#include <cstring>#include <vector> using namespace std;#define N 1009struct POINT{       int x, y;}; int p[N];POINT a[N];vector<int>  adj[N];bool good[N]; bool okdis(POINT& a, POINT& b, int d){        return (a.x - b.x) * (a.x - b.x)  +  (a.y - b.y) * (a.y - b.y) <= d * d ? true: false;} int find(int x){return p[x] == x? x : p[x] = (find(p[x]));} int main(){     int  n, d;   //  FILE* fp = fopen("in.txt", "r");      scanf( "%d %d", &n, &d);     for (int i = 1; i <= n; i++)     {           scanf("%d %d", &a[i].x, &a[i].y);           adj[i].clear();           p[i] = i;           good[i] = 0;      }     for (int i = 1; i <= n; i++)         for (int j = i + 1; j <= n; j++)         {               if (okdis(a[i], a[j], d))                   adj[i].push_back(j), adj[j].push_back(i);         }     char op[3];     int jia, yi;     while (scanf( "%s %d", op, &jia) == 2)     {           if (op[0] == 'O')            {                     good[jia] = true;                      for (int i = 0; i < adj[jia].size(); i++)                     {                            if (good[adj[jia][i]] == false)continue;                             int y = find (adj[jia][i]);                            int x = find(jia);                            p[x] = y;                     }            }            else{                scanf( "%d", &yi);                 int x = find(jia), y = find(yi);                if (x == y)puts("SUCCESS");                else puts("FAIL");           }      }    // getchar();      return 0;}