OJ-Problems-Source/POJ/1182.cpp

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2016-05-01 14:25:04 +08:00
#include <cstdio>
using namespace std;
#define MAXN 50005
int father[MAXN];
///Relationship: 0 Same 1 Father--eat-->son 2 son--eat-->father
int relation[MAXN];
int find(int pos)
{
if(father[pos]!=pos)
{
int x=father[pos];
father[pos]=find(x);
relation[pos]=(relation[pos]+relation[x])%3;
}
return father[pos];
}
int main()
{
int N,K;
scanf("%d %d",&N,&K);
{
/// Init
for(int i=0; i<=N; i++)
{
relation[i]=0;
father[i]=i;
}
int a,b,c;
int cnt=0;
for(int i=0;i<K;i++)
{
scanf("%d %d %d",&a,&b,&c);
if(a==2&&b==c)
{
++cnt;continue;
}
if(b>N||c>N)
{
++cnt;continue;
}
int rootfather_b=find(b);
int rootfather_c=find(c);
if(rootfather_b==rootfather_c)
{
if(a==1&&relation[b]!=relation[c])
{
++cnt;continue;
}
if(a==2&&relation[b]!=(relation[c]+2)%3)
{
++cnt;continue;
}
}
else
{
father[rootfather_c]=rootfather_b;
relation[rootfather_c]=(relation[b] + (a-1) + (3-relation[c])) % 3;
}
}
printf("%d\n",cnt);
}
return 0;
}