对于并查集深深的恐惧，求助

BeingErnest @ 2018-10-29 14:06:15

#include<cstdio>
#include<algorithm>
using namespace std;
int father[10001];
int xz(int x)
{
if(father[x]==x) return x;
return father[x]=xz(father[x]);
}
int main()
{
int n,m;
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
{
    father[i]=i;
}
for(int i=1;i<=m;i++)
{
    int x,y,z;
    scanf("%d%d%d",&z,&x,&y);
    if(z==1)
    {
        father[x]=xz(y);
    }
    else
    {
        int a;
        a=xz(x);
        int b;
        b=xz(y);
        if(a==b)
            printf("Y\n");
        else
            printf("N\n");
    }
}
return 0;
} 

by info___tion @ 2018-10-29 14:11:04

father[x]=xz(y);

你这句话不是应该这么写吗：

father[xz(x)]=xz(y);

by 一叶知秋。 @ 2018-10-29 14:11:50

 father[x]=xz(y);

是

father[xz(x)]=xz(y)

by 一叶知秋。 @ 2018-10-29 14:12:03

@铭玘

by Ghoster @ 2018-10-29 14:12:59

if(z==1)
    {
        father[xz(x)]=xz(y);
    }

把这改一下就A了

by 只用函数 @ 2018-10-29 14:13:00

@铭玘 没错没错就是这里

by jeffqi @ 2018-10-29 14:14:18

@铭玘

if(z==1)
{
    father[x]=xz(y);
}

改成

if(z==1)
{
    father[xz(x)]=xz(y);
}

就能过

by foreverlasting @ 2018-10-29 14:15:40

建议写成非递归版 ：``` while(x!=fa[x])x=fa[x]=fa[fa[x]]; return x;

by BeingErnest @ 2018-10-29 14:17:14

@加藤圣教_封仙 是因为容易递归层次溢出？

by foreverlasting @ 2018-10-29 14:17:58

@铭玘 而且非递归版跑得快，又不会爆栈

by BeingErnest @ 2018-10-29 14:17:59

感谢各位，我忽略了只能爸爸认爸爸，