POJ_1182_食物链

//见《挑战程序设计竞赛》第2.4.4节

#include<cstdio>
using namespace std;

#define MAX_N 150001
#define MAX_K 100000

int par[MAX_N];
int rank[MAX_N];

void init(int n) {
	for (int i = 0; i < n; i++) {
		par[i] = i;
		rank[i] = 0;
	}
}

int find(int x) {
	if (par[x] == x) {
		return x;
	}
	else {
		return par[x] = find(par[x]);
	}
}

void unite(int x, int y) {
	x = find(x);
	y = find(y);
	if (x == y) return;

	if (rank[x] < rank[y]) {
		par[x] = y;
	}
	else {
		par[y] = x;
		if (rank[x] == rank[y]) rank[x]++;
	}
}

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

int N, K;
int t, x, y;

int main() {
	scanf("%d%d", &N, &K);

	init(N * 3 + 1);

	int ans = 0;
	for (int i = 0; i < K; i++) {
		scanf("%d%d%d", &t, &x, &y);

		if (x < 1 || x > N || y < 1 || y > N){
			ans++;
			continue;
		}

		if (t == 1) {
			if (same(x, y + N) || same(x + N, y)) {
				ans++;
			}
			else {
				unite(x, y);
				unite(x + N, y + N);
				unite(x + N * 2, y + N * 2);
			}
		}
		else {
			if (same(x, y) || same(x + N, y)) {
				ans++;
			}
			else {
				unite(x, y + N);
				unite(x + N, y + 2 * N);
				unite(x + 2 * N, y);
			}
		}
	}

	printf("%d\n", ans);

	return 0;
}