Submission #878385

#	Time	Username	Problem	Language	Result	Execution time	Memory
878385		SanguineChameleon	Closing Time (IOI23_closing)	C++17	83 / 100	1035 ms	55840 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
using namespace std;

const long long inf = 1e18L + 20;

namespace cardboard {
	vector<pair<int, long long>> boxes;

	bool cmp(pair<int, int> p1, pair<int, int> p2) {
		return boxes[p1.second].second - boxes[p1.first].second > boxes[p2.second].second - boxes[p2.first].second;
	}

	int solve(int N, long long K, vector<pair<long long, long long>> costs) {
		vector<pair<long long, int>> order(N << 1);
		for (int i = 0; i < N; i++) {
			order[i << 1] = {costs[i].first << 1, i << 1};
			order[i << 1 | 1] = {costs[i].second, i << 1 | 1};
		}
		sort(order.begin(), order.end());
		vector<pair<int, int>> ids(N);
		boxes.resize(N << 1);
		for (int i = 0; i < (N << 1); i++) {
			if (order[i].second & 1) {
				boxes[i] = {2, order[i].first};
				ids[order[i].second >> 1].second = i;
			}
			else {
				boxes[i] = {1, order[i].first >> 1};
				ids[order[i].second >> 1].first = i;
			}
		}
		sort(ids.begin(), ids.end(), cmp);
		vector<long long> cur_dp = {0};
		for (int i = 0; i < N; i++) {
			vector<long long> nxt_dp = cur_dp;
			nxt_dp.resize((int)nxt_dp.size() + 2, inf);
			for (int j = 0; j < (int)cur_dp.size(); j++) {
				nxt_dp[j + 1] = min(nxt_dp[j + 1], cur_dp[j] + boxes[ids[i].first].second);
				nxt_dp[j + 2] = min(nxt_dp[j + 2], cur_dp[j] + boxes[ids[i].second].second);
			}
			cur_dp.swap(nxt_dp);
		}
		for (int i = N * 2; i >= 0; i--) {
			if (cur_dp[i] <= K) {
				return i;
			}
		}
		return 0;
	}
}

namespace tree {
	vector<vector<pair<int, int>>> adj;

	void init(int N) {
		adj.resize(N);
		for (int i = 0; i < N; i++) {
			adj[i].clear();
		}
	}

	void add_edge(int u, int v, int w) {
		adj[u].emplace_back(v, w);
		adj[v].emplace_back(u, w);
	}

	void dfs(int u, int p, vector<long long> &dist) {
		for (auto [v, w]: adj[u]) {
			if (v != p) {
				dist[v] = dist[u] + w;
				dfs(v, u, dist);
			}
		}
	}
}

int max_score(int N, int X, int Y, long long K, vector<int> U, vector<int> V, vector<int> W) {
	tree::init(N);
	for (int i = 0; i < N - 1; i++) {
		tree::add_edge(U[i], V[i], W[i]);
	}
	vector<long long> distX(N), distY(N);
	tree::dfs(X, -1, distX);
	tree::dfs(Y, -1, distY);
	vector<long long> dists(distX.begin(), distX.end());
	dists.insert(dists.end(), distY.begin(), distY.end());
	sort(dists.begin(), dists.end());
	int res = 0;
	long long sum = 0;
	for (auto d: dists) {
		if (sum + d <= K) {
			sum += d;
			res++;
		}
		else {
			break;
		}
	}
	int cnt = 0;
	vector<pair<long long, long long>> costs(N);
	for (int i = 0; i < N; i++) {
		if (distX[i] + distY[i] == distX[Y]) {
			cnt++;
			K -= min(distX[i], distY[i]);
			costs[i] = {max(distX[i], distY[i]) - min(distX[i], distY[i]), inf};
		}
		else {
			costs[i] = {min(distX[i], distY[i]), max(distX[i], distY[i])};
		}
	}
	if (K >= 0) {
		res = max(res, cnt + cardboard::solve(N, K, costs));
	}
	return res;
}

• 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