제출 #526623

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
526623		sliviu	꿈 (IOI13_dreaming)	C++17	24 / 100	183 ms	24572 KiB

dreaming

#include <dreaming.h>
#include <bits/stdc++.h>

using namespace std;

int travelTime(int n, int m, int cost, int A[], int B[], int T[]) {
	int ans = 0, t = 0;
	vector<int> seen(n), dpu(n), dpb(n), cn;
	vector<vector<int>> pref(n), suf(n);
	vector<pair<int, int>> cur;
	vector<vector<pair<int, int>>> G(n);
	for (int i = 0; i < m; ++i) {
		G[A[i]].emplace_back(B[i], T[i]);
		G[B[i]].emplace_back(A[i], T[i]);
	}
	function<void(int, int)> dfs = [&](int node, int last) {
		cn.emplace_back(node);
		seen[node] = t;
		pref[node].emplace_back(0), suf[node].emplace_back(0);
		for (auto x : G[node])
			if (x.first != last) {
				dfs(x.first, node);
				dpb[node] = max(dpb[node], dpb[x.first] + x.second);
				pref[node].emplace_back(dpb[x.first] + x.second);
				suf[node].emplace_back(dpb[x.first] + x.second);
			}
		pref[node].emplace_back(0), suf[node].emplace_back(0);
		int s = pref[node].size() - 1;
		for (int i = 1; i <= s; ++i)
			pref[node][i] = max(pref[node][i], pref[node][i - 1]);
		for (int i = s; i; --i)
			suf[node][i] = max(suf[node][i], suf[node][i + 1]);
	};
	function<void(int, int)> dfs2 = [&](int node, int last) {
		int ct = 1;
		for (auto x : G[node])
			if (x.first != last) {
				dpu[x.first] = x.second + max(max(pref[node][ct - 1], suf[node][ct + 1]), dpu[node]);
				dfs2(x.first, node);
				++ct;
			}
	};
	for (int i = 0; i < n; ++i)
		if (!seen[i]) {
			++t;
			cn.clear();
			dfs(i, -1);
			dfs2(i, -1);
			pair<int, int> ans = {INT_MAX, 0};
			//cout << "ROOT : " << i << '\n';
			for (auto x : cn)
				//printf("%d : U %d D %d\n", x, dpu[x], dpb[x]);
				ans = min(ans, {max(dpu[x],dpb[x]),x});
			cur.emplace_back(ans);
			//cout << ans.first << ' ' << ans.second << '\n';
		}
	pair<int, int> node = cur.back();
	cur.pop_back();
	for (auto [c, n] : cur) {
		//cout << "ADD " << n << ' ' << node.second << '\n';
		G[n].emplace_back(node.second, cost);
		G[node.second].emplace_back(n, cost);
		if (c < node.second)
			node.first = max(node.first, c + cost);
		else
			node.first = max(node.first, c + cost), node.second = n;
	}
	dpb.assign(n, 0), dpu.assign(n, 0);
	pref.assign(n, vector<int>()), suf.assign(n, vector<int>());
	dfs(0, -1);
	dfs2(0, -1);
	for (int i = 0; i < n; ++i)
		ans = max(ans, dpu[i] + dpb[i]);
	return ans;
}

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 0 / 23
• Subtask 4: 0 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23