【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 + 10;
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 = 0 ; i < maxn; ++ i) {
            father[i] = i;
            ans[i] = 1;
        }

        int x, y, MAXX = 0;
        res = 1;
        for (int i = 0 ; i < n; ++ i) {
            scanf("%d%d", &x, &y);
            Union (x, y);
            MAXX = max(x, MAXX);
            MAXX = max(y, MAXX);
        }

        cout << res << endl;
    }
    return 0;
}