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OI-codes/Luogu/problem/P3275/P3275.cpp

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2021-07-15 12:48:00 +00:00
#include <bits/stdc++.h>
using namespace std;
int n, m, x, a, b, head[300005], vis[300005], used[300005], dis[300005], num;
queue<int> q;
struct {
int next, to, val;
} g[1000005];
void add(int u, int v, int w) {
g[++num].next = head[u];
g[num].to = v;
g[num].val = w;
head[u] = num;
}
int main() {
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> x >> a >> b;
if (x == 1) {
add(a, b, 0);
add(b, a, 0);
} else if (x == 2) {
add(a, b, 1);
} else if (x == 3) {
add(b, a, 0);
} else if (x == 4) {
add(b, a, 1);
} else if (x == 5) {
add(a, b, 0);
}
if (x % 2 == 0 && a == b) {
cout << -1 << endl;
exit(0);
}
}
for (int i = 1; i <= n; i++) {
vis[i] = 1;
dis[i] = 1;
used[i] = 1;
q.push(i);
}
while (!q.empty()) {
int z = q.front();
q.pop();
if (used[z] >= n - 1) {
cout << -1 << endl;
exit(0);
}
used[z]++;
for (int i = head[z]; i; i = g[i].next) {
int t = g[i].to;
if (dis[t] < dis[z] + g[i].val) {
dis[t] = dis[z] + g[i].val;
if (!vis[t]) {
q.push(t);
vis[t] = 1;
}
}
}
vis[z] = 0;
}
long long ans = 0;
for (int i = 1; i <= n; i++) {
ans += dis[i];
}
cout << ans << endl;
return 0;
}