POJ 1611 The Suspects(特别无语的并查集)

很简单的一道题目，开始用的是并查集的分离集合森林做，不知道怎么的特别不稳定，太奇怪了，WA无数次，无奈之下改成一维数组了。。sad

AC

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <math.h>
#define PI acos(-1,0)
using namespace std;
const int maxn = 30010;
const int maxm = 100001;
#define lson left, m, id<<1
#define rson m+1, right, id<<1|1
#define min(a,b) (a>b)?b:a
#define max(a,b) (a>b)?a:b
using namespace std;

int father[50000];
int num[50000],n,m;

int Find(int r)
{
int i = r,j;
while(father[r]!=r)
{
r=father[r];
}

while(father[i]!=r)
{
j = father[i];
father[i] = r;
i = j;
}
return r;
}

void init()
{
for(int i = 0;i < n;i++)
{
father[i] = i;
num[i] = 1;
}
}
void Merge(int l,int b)
{
int y = Find(b);
if(l != y)
{
father[y] = l;
num[l] +=  num[y];
}
}
int main()
{
int j,k,l;
while(~scanf("%d%d",&n,&m))
{
if(n==0 && m==0)
break;
init();
int b;
while(m--)
{
scanf("%d%d",&k,&l);

int x = Find(l);
for(j = 1;j < k;j++)
{
scanf("%d",&b);
Merge(x,b);
}

}
printf("%d\n",num[Find(0)]);
}
return 0;
}

WA

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <math.h>
#define PI acos(-1,0)
using namespace std;
const int maxn = 30010;
const int maxm = 100001;
#define lson left, m, id<<1
#define rson m+1, right, id<<1|1
#define min(a,b) (a>b)?b:a
#define max(a,b) (a>b)?a:b

using namespace std;

struct node
{
int zhi , parent;
} T[maxn];

int Find(int x)
{
return (x == T[x].parent) ? x : Find(T[x].parent);
}

void Merge(int x,int y)
{
int fx,fy;

fx = Find(x);
fy = Find(y);
if(fx!=fy)
{
T[fy].parent = fx;
T[fx].zhi += T[fy].zhi;
}
}

int main()
{
int m,n,k;
while (~scanf("%d%d",&n,&m))
{
if (n==0 && m==0) break;

for(int j = 0; j<n; j++)
{
T[j].zhi = 1;
T[j].parent = j;
}
for(int i = 1; i <= m; ++i)
{
scanf("%d", &k);
int *aa = new int[k];
for(int j = 0; j < k; ++j)
{
scanf("%d", &aa[j]);
if(j != 0)
Merge(aa[j - 1], aa[j]);
}
delete(aa);
}
printf("%d\n",T[T[0].parent].zhi);

}
return 0;
}

5 3

1 2

2 0 1

3 1 4 5

answer  3

有时是正确结果，有时不是，特别无语啊。

3