too many or too few lines?

评测后WA了三个点，全是too many or too few lines。大神帮看看。

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cmath>
#include<algorithm>
int pre[1000005],K,N,b,c,z;
using namespace std;
int mix(int x)
{
if(x!=pre[x])
return pre[x]=mix(pre[x]);
}
int jo(int x,int y)
{
int a=mix(x),b=mix(y);
if(a==b)
return 1;
pre[a]=b;
return 0;
}
int main ()
{
scanf("%d%d",&N,&K);
for(int a=0;a<=K;a++)
pre[a]=a;
for(int a=0;a<K;a++)
{
scanf("%d%d%d",&z,&b,&c);
if(z==1)
jo(b,c);
if(z==2)
if((mix(b))==(mix(c)))
printf("Y\n");
else
printf("N\n");
}
return 0;
}