食物链 POJ - 1182

Posted 2021-03-13 qingyuyyyyy

#include<iostream>
#include<cstdio>
using namespace std;
const int N=100010;
int p[N];
int d[N];
int find(int x)
{
    if(p[x]!=x)
    {
        int u=find(p[x]);
        d[x]+=d[p[x]];
        p[x]=u;
    }
    return p[x];
}
int main()
{
    int n,k;
    int res=0;
    cin>>n>>k;
    for(int i=1;i<=n;i++)
        p[i]=i;
    while(k--)
    {
        int t,x,y;
        scanf("%d%d%d",&t,&x,&y);
        if(x>n||y>n)
        {
            res++;
            continue;
        }
        int fx=find(x);
        int fy=find(y);
        if(t==1)
        {
            if(fx==fy)
            {
                if((d[x]-d[y])%3)
                    res++;
            }
            else
            {
                p[fx]=fy;
                d[fx]=d[y]-d[x];
            }
        }
        else if (t==2)
        {
            if(fx==fy)
            {
                if((d[x]-d[y]-1)%3)
                    res++;
            }
            else
            {
                p[fx]=fy;
                d[fx]=d[y]-d[x]+1;
            }
        }
    }
    printf("%d",res);
    return 0;
}