POJ 1182（并查集）

// 并查集
#include <iostream>
#include <cstdio>
using namespace std;
#define maxn 50050

int p[maxn];
int N, K;
int d, x, y;
int ans = 0;

int find(int x)
{
return p[x] == x ? x:p[x]=find(p[x]);
}

bool same(int x,int y)
{
return find(x) == find(y);
}

void unite(int x,int y)
{
x = find(x);
y = find(y);
if(x != y)
p[x] = y;
}

void slove()
{
for(int i = 1; i <= 3*N; i++)
p[i] = i;
while(K--)
{
cin>>d>>x>>y;
if(x<0 || x>N || y<0 || y>N)
{
ans++;
continue;
}
if(d == 1)
{
if(same(x,y+N) || same(x,y+2*N))
ans++;
else
{
unite(x,y);
unite(x+N,y+N);
unite(x+2*N,y+2*N);
}
}
else
{
if(same(x,y) || same(x,y+2*N))
ans++;
else
{
unite(x,y+N);
unite(x+N,y+2*N);
unite(x+2*N,y);
}
}
}
printf("%d\n",ans);
}

int main()
{
cin>>N>>K;
slove();

return 0;
}
/*
测试数据；
100 7
1 101 1
2 1 2
2 2 3
2 3 3
1 1 3
2 3 1
1 5 5
*/