Submission #563998

#	Time	Username	Problem	Language	Result	Execution time	Memory
563998		hollwo_pelw	Beads and wires (APIO14_beads)	C++17	0 / 100	5 ms	8148 KiB

beads

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/trie_policy.hpp>
// #include <ext/rope>

using namespace std;
// using namespace __gnu_cxx;
// using namespace __gnu_pbds;

void Hollwo_Pelw();

signed main(){
#ifndef hollwo_pelw_local
	if (fopen(".inp", "r"))
		assert(freopen(".inp", "r", stdin)), assert(freopen(".out", "w", stdout));
#else
	using namespace chrono;
	auto start = steady_clock::now();
#endif
	cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
	int testcases = 1;
	// cin >> testcases;
	for (int test = 1; test <= testcases; test++){
		// cout << "Case #" << test << ": ";
		Hollwo_Pelw();
	}
#ifdef hollwo_pelw_local
	auto end = steady_clock::now();
	cout << "\nExecution time : " << duration_cast<milliseconds> (end - start).count() << "[ms]" << endl;
#endif
}

const int N = 2e5 + 5;

int n, dp[N][4];
vector<pair<int, int>> adj[N];

void solve(int u, int p) {
	dp[u][0] = 0;
	for (auto [v, w] : adj[u]) if (v != p) {
		solve(v, u);
		for (int i = 4; i --; ) {
			if (i < 3) {
				dp[u][i + 1] = max({
					dp[u][i + 1],
					dp[u][i] + w + max(dp[v][0], dp[v][2]),
				});
			}

			dp[u][i] = max({
				dp[u][i],
				dp[u][i] + max(dp[v][0], dp[v][2]),
				dp[u][i] + w + max(dp[v][1], dp[v][3])
			});
		}
	}
}

void Hollwo_Pelw(){
	cin >> n;
	memset(dp, -0x3f, sizeof dp);
	for (int i = 1, u, v, w; i < n; i++) {
		cin >> u >> v >> w;
		adj[u].emplace_back(v, w);
		adj[v].emplace_back(u, w);
	}
	solve(1, 0);
	cout << max({dp[1][0], dp[1][2]});
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43