【HDU1856】More is better（并查集基础题）

裸并查集，但有二坑：

1.需要路径压缩，不写的话会TLE

2.根据题目大意，如果0组男孩合作的话，应该最大的子集元素数目为1.所以res初始化为1即可。

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

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

 const int maxn = 1e7 + ;
 int father[maxn], ans[maxn], res;

 int getFather (int x) {
     if (x != father[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;
         ans[x] += ans[y];
         res = max (ans[x], res);
     }
 }

 int main () {
     int n;
     while (~scanf("%d", &n)) {
         for (int i =  ; i < maxn; ++ i) {
             father[i] = i;
             ans[i] = ;
         }

         int x, y, MAXX = ;
         res = ;
         for (int i =  ; i < n; ++ i) {
             scanf("%d%d", &x, &y);
             Union (x, y);
             MAXX = max(x, MAXX);
             MAXX = max(y, MAXX);
         }

         cout << res << endl;
     }
     return ;
 }