【并查集】 hdu 1856 More is better

#include <iostream>
#include <math.h>
#include <algorithm>
#include <string.h>
#include <stdio.h>
using namespace std;

int father[10000005], cnt[10000005];

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

int main()
{
int n;
while(scanf("%d", &n) != EOF)
{
for(int i = 0; i <= 10000000; i ++)
{
father[i] = i;
cnt[i] = 1;
}

int maxx = 0;
while(n--)
{
int a, b;
scanf("%d%d", &a, &b);
maxx = maxx > a? maxx: a;
maxx = maxx > b? maxx: b;
a = fi(a);
b = fi(b);
if(a != b)
{
father[a] = b;
cnt[b] += cnt[a];   /*合并集合中元素个数*/
}
}
int ans = 1;    //即使n == 0 也输出1
for(int i = 1; i <= maxx; i ++)
if(cnt[i] > ans)
ans = cnt[i];
printf("%d\n", ans);
}
return 0;
}