【HDU1232】畅通工程（并查集基础题）

裸敲并查集，很水一次AC

 #include <iostream>
 #include <cstring>
 #include <cstdlib>
 #include <cstdio>
 #include <cctype>
 #include <cmath>
 #include <algorithm>
 #include <numeric>
 #include <string>

 #pragma comment(linker, "/STACK:102400000,102400000")
 using namespace std;

 int cnt = ;
 const int V = ;
 int father[V];

 int getFather (int x) {
     if (father[x] != x) {
         father[x] = getFather (father[x]);
     }
     return father[x];
 }

 void Union (int p, int q) {
     int x = getFather (p);
     int y = getFather (q);
     if (x != y) {
         father[y] = x;
         cnt ++;
     }
 }

 int main () {
     int n, road_n;
     while (~scanf("%d", &n)) {
         if (!n) break;
         scanf("%d", &road_n);//cin >> road_n;
         cnt = ;
         for (int i = ; i <= n; ++ i) {
             father[i] = i;
         }

         for (int i =  ; i < road_n; ++ i) {
             int x, y; //cin >> x >> y;
             scanf("%d%d", &x, &y);
             Union (x, y);
         }
         //cout << "cnt :   " << cnt << endl;
         cout << n -  - cnt << endl;
     }
     return ;
 }