Submission #983001

#	Time	Username	Problem	Language	Result	Execution time	Memory
983001		vjudge1	Duathlon (APIO18_duathlon)	C++17	0 / 100	36 ms	16412 KiB

count_triplets

#include <bits/stdc++.h>
#define int long long
using namespace std;
int n, m, i, j, x, y, ans, sz[200001];
bool u[200001];
vector<int> g[200001];

void dfs(int x) {
	sz[x] = 1;
	u[x] = 1;
	for (auto y : g[x]) {
		if (u[y]) continue;
		dfs(y);
		sz[x] += sz[y];
	}
}

signed main() {
	cin.tie(0)->sync_with_stdio(0);
	#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	#endif
	cin >> n >> m;
	while (m--) {
		cin >> x >> y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	dfs(1);
	for (i = 1; i <= n; i++) {
		ans += (sz[i] - 1) * (sz[1] - sz[i]);
	}
	cout << n * (n - 1) - ans;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10