cdoj1100 并查集

http://acm.ccucomp.cn/acmhome/problemdetail.do?&method=showdetail&id=1100

下面代码错了！！！！只是在学校oj上面ac了

#include <iostream>
#include <math.h>
using namespace std;
typedef struct node
{
    int pre;
    int next;
    int v;
}Lan;
Lan lan[50001];
int Find(int n)
{
    int f;
    f=n;
    while(f!=lan[f].v)
        f=lan[f].v;
    return f;
}
void Merge(int x,int y)
{
     lan[x].v=y;
     if(lan[y].pre==0)
     lan[y].pre=lan[x].pre;
     if(lan[y].next==0)
     lan[y].next=lan[x].next;
     
}

int main()
{
    int n,k;
    int count;
    while(cin>>n>>k)
    {
        count=0;
        int i,j,x,y,d;
        //memset(flag,0,sizeof(flag));
        for(i=0;i<=n;i++)
        {
            lan[i].v=i;
            lan[i].pre=0;
            lan[i].next=0;
        }
        
        int findx,findy;
        for(i=0;i<k;i++)
        {
            cin>>d>>x>>y;
            if(x>n||y>n)
            {    count++;continue;  }
            if(d==2&&x==y)
            {    count++;continue;  }
            if(d==1)
            {//    if(!Merge(x,y))
                findx=Find(x);
                findy=Find(y);
                if(lan[findx].pre==findy||lan[findx].next==findy)
                   count++;
                else
                   Merge(findx,findy);
            }
            if(d==2)
            {
               findx=Find(x);
               findy=Find(y);
               if(findx==findy||lan[findx].pre==findy)
                   count++;
               else
               {
                   if(lan[findy].pre!=0)
                       Merge(findx,lan[findy].pre);
                   if(lan[findx].next!=0)
                       Merge(findy,lan[findx].next);
                   lan[findx].next=findy;
                   lan[findy].pre=findx;
                   
               }/////////////
               
            }
            
        }
    cout<<count<<endl;
    }

    return 0;
}