Submission #1066043

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066043		Gromp15	Closing Time (IOI23_closing)	C++17	83 / 100	1051 ms	566168 KiB

closing

#include <bits/stdc++.h>
#include "closing.h"
#define ar array
#define ll long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using namespace std;
template<typename T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<typename T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }
 
const ll INF = 1e18;
 
int max_score(int n, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W) {
	vector<vector<ar<int, 2>>> adj(n+1);
	for (int i = 0; i < n-1; i++) {
		adj[U[i]].push_back({V[i], W[i]});
		adj[V[i]].push_back({U[i], W[i]});
	}
	vector<vector<ll>> d(2, vector<ll>(n, INF));
	vector<int> p(n, -1);
	auto dfs = [&](auto&& s, int v, vector<ll>& dist) -> void {
		for (auto [u, w] : adj[v]) if (u != p[v]) {
			p[u] = v, dist[u] = dist[v] + w;
			s(s, u, dist);
		}
	};
	d[0][X] = 0, d[1][Y] = 0;
	dfs(dfs, X, d[0]);
	fill(all(p), -1);
	dfs(dfs, Y, d[1]);
	if (d[0][Y] > 2*K) {
		vector<ll> D(2*n);
		for (int i = 0; i < n; i++) D[i] = d[0][i], D[i+n] = d[1][i];
		sort(all(D));
		int ans = 0;
		for (auto x : D) {
			if (K - x >= 0) {
				K -= x, ans++;
			}
			else break;
		}
		return ans;
	}
	vector<vector<ar<ll, 4>>> dp(n, vector<ar<ll, 4>>(2*n+1, {INF, INF, INF, INF}));
	vector<int> tin(n), tout(n), sub(n);
	int timer = 0;
	auto dfs3 = [&](auto&& s, int v, int px) -> void {
		tin[v] = timer++, sub[v] = 1;
		for (auto [u, w] : adj[v]) if (u != px) {
			s(s, u, v);
			sub[v] += sub[u];
		}
		tout[v] = timer-1;
	};
	dfs3(dfs3, X, -1);
	auto anc = [&](int x, int y) {
		return tin[x] <= tin[y] && tout[y] <= tout[x];
	};
	auto dfs2 = [&](auto&& s, int v, int px) -> void {
		dp[v][0][0] = 0;
		dp[v][1][1] = d[0][v];
		dp[v][1][2] = d[1][v];
		dp[v][2][3] = max(d[0][v], d[1][v]);
		int tot = 2;
		sort(all(adj[v]), [&](auto x, auto y) { return anc(x[0], Y) != anc(y[0], Y) ? anc(x[0], Y) : x[0] < y[0]; });
		for (auto [u, w] : adj[v]) if (u != px) {
			s(s, u, v);
			assert(tot <= 2*n);
			for (int i = tot; i >= 0; i--) {
				for (int j = 2*sub[u]; j >= 0; j--) {
					assert(i+j<=2*n);
					ckmin(dp[v][i+j][0], dp[v][i][0] + dp[u][j][0]);
					if (anc(u, Y)) ckmin(dp[v][i+j][0], dp[v][i][0] + dp[u][j][2]);

					ckmin(dp[v][i+j][1], dp[v][i][1] + dp[u][j][0]);
					ckmin(dp[v][i+j][1], dp[v][i][1] + dp[u][j][1]);
					if (anc(u, Y)) {
						ckmin(dp[v][i+j][1], dp[v][i][1] + dp[u][j][2]);
						ckmin(dp[v][i+j][1], dp[v][i][1] + dp[u][j][3]);
					}
					
					if (anc(u, Y)) {
						if (i == 1) dp[v][i+j][2] = dp[v][i][2] + dp[u][j][2];
					}
					else {
						ckmin(dp[v][i+j][2], dp[v][i][2] + dp[u][j][0]);
						ckmin(dp[v][i+j][2], dp[v][i][2] + dp[u][j][2]);
					}

					if (anc(u, Y)) {
						if (i == 2) dp[v][i+j][3] = dp[v][i][3] + min(dp[u][j][2], dp[u][j][3]);
					}
					else {
						ckmin(dp[v][i+j][3], dp[v][i][3] + dp[u][j][0]);
						ckmin(dp[v][i+j][3], dp[v][i][3] + dp[u][j][1]);
						ckmin(dp[v][i+j][3], dp[v][i][3] + dp[u][j][2]);
						ckmin(dp[v][i+j][3], dp[v][i][3] + dp[u][j][3]);
					}
				}
			}
			tot += 2*sub[u];
		}
	};
	dfs2(dfs2, X, -1);
	int ans = 0;
	for (int j = 1; j <= 2*n; j++) for (int k = 0; k < 4; k++) if (dp[X][j][k] <= K) ckmax(ans, j);
	return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 9 / 9
• Subtask 6: 11 / 11
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 0 / 17