带权并查集模板（poj1182食物链验证）

#include<stdio.h>
using namespace std;

int a,b,error=0;
int n,k,set[50500];
int rank[50500];
int d,x,y;

long findset(int x){
int y=x;
if(set[x]==x) return x;
else y=findset(set[x]);
rank[x]=(rank[set[x]]+rank[x])%3;
set[x]=y;
return y;
}

void unions(int x,int y,int w){
//long a,b;
a=findset(x);
b=findset(y);
set[b]=a;
rank[b]=(rank[x]-rank[y]+w+3)%3;

}

int main(){
scanf("%d %d",&n,&k);
for(int i=0;i<n;i++){
set[i]=i;
rank[i]=0;
}
//cout<<n<<k;
for(int i=0;i<k;i++){
scanf("%d %d %d",&d,&x,&y);
//cin>>d>>x>>y;
if(x>n||y>n) {error++; continue;}
a=findset(x);
b=findset(y);
if(a==b){
if(d==1&&rank[x]!=rank[y]){error++; continue;}
if(d==2&&(rank[x]+1)%3!=rank[y]){error++; continue;}
}
unions(x,y,d-1);
}
cout<<error;
return 1;
}