食物链

#include<stdio.h>
#include<algorithm>
#include<iostream>
#include<string.h>

using namespace std;

int fa[50110];
int rel[50110];

int N;

void init()
{
    for(int i=0;i<=N+3;i++)
    {
        fa[i]=i;
        rel[i]=0;
    }
}

int find(int x)
{
    if(x!=fa[x])
    {
        int fx=find(fa[x]);
        rel[x]=(rel[x]+rel[fa[x]])%3;
        fa[x]=fx;
    }
    return fa[x];
}

int main()
{
    int k;
    scanf("%d%d",&N,&k);
    init();
    int d,X,Y;
    int s=0;
    for(int i=1;i<=k;i++)
    {
        scanf("%d%d%d",&d,&X,&Y);
        if(X>N||Y>N)
        {
            s++;
            continue;
        }
        if(d==2&&X==Y)
        {
            s++;
            continue;
        }
        int a=find(X);
        int b=find(Y);
        if(a==b)
        {
            if(d-1!=(rel[Y]-rel[X]+3)%3)
                s++;
        }
        else
        {
            fa[b]=a;
            rel[b]=(rel[X]+d-1+(3-rel[Y]))%3;
        }
    }
    printf("%d",s);
    return 0;
}