제출 #829756

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
829756		caganyanmaz	Duathlon (APIO18_duathlon)	C++14	0 / 100	1090 ms	1048576 KiB

count_triplets

#include <bits/stdc++.h>
#define int int64_t
#define pb push_back
using namespace std;

constexpr static int MXN = 1e5;
int n, m;
vector<int> g[MXN];
int subtree_size[MXN];

int res;
void dfs(int node, int p)
{
	subtree_size[node] = 1;
	for (int c : g[node])
	{
		if (c == p)
			continue;
		dfs(c, node);
		subtree_size[node] += subtree_size[c];
		res += subtree_size[c] * (n - subtree_size[c] - 1);
	}
	int rem = n - subtree_size[node];
	res += (subtree_size[node] - 1) * rem;
}

int32_t main()
{
	cin >> n >> m;
	for (int i = 0; i < m; i++)
	{
		int a, b;
		cin >> a >> b;
		a--,b--;
		g[a].pb(b);
		g[b].pb(a);
	}
	dfs(0, 0);
	cout << res << "\n";
}

• 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