Submission #611138

#TimeUsernameProblemLanguageResultExecution timeMemory
611138TemmieRoller Coaster Railroad (IOI16_railroad)C++17
64 / 100
429 ms65660 KiB
#include <bits/stdc++.h>

long long sub12(int n, std::vector <int> s, std::vector <int> t) {
	t.push_back(1);
	long long dp[1 << 16][17];
	for (int mask = 0; mask < (1 << 16); mask++) {
		for (int i = 0; i < 17; i++) {
			dp[mask][i] = 1LL << 60;
		}
	}
	for (int i = 0; i < 17; i++) {
		dp[(1 << n) - 1][i] = 0;
	}
	auto f = [&] (auto&& self, int mask, int last) -> long long {
		if (dp[mask][last] < (1LL << 60)) {
			return dp[mask][last];
		}
		for (int i = 0; i < n; i++) {
			if (mask & (1 << i)) {
				continue;
			}
			dp[mask][last] = std::min(dp[mask][last], self(self, mask | (1 << i), i) + std::max(0, t[last] - s[i]));
		}
		return dp[mask][last];
	};
	return f(f, 0, n);
}

long long plan_roller_coaster(std::vector <int> s, std::vector <int> t) {
	int n = s.size();
	if (n <= 16) {
		return sub12(n, s, t);
	}
	std::vector <int> ep { 0, (int) 1e9 };
	for (int i = 0; i < n; i++) {
		ep.push_back(s[i]);
		ep.push_back(t[i]);
	}
	std::sort(ep.begin(), ep.end());
	{
		std::vector <int> tmp;
		for (int x : ep) {
			if (tmp.empty() || x != tmp.back()) {
				tmp.push_back(x);
			}
		}
		ep = tmp;
	}
	std::vector <std::vector <int>> g(ep.size()), h(ep.size());
	std::vector <int> din(ep.size(), 0), dou(ep.size(), 0);
	g[(int) ep.size() - 1].push_back(0);
	h[0].push_back((int) ep.size() - 1);
	din[0]++;
	dou[(int) ep.size() - 1]++;
	for (int i = 0; i < n; i++) {
		int u = std::lower_bound(ep.begin(), ep.end(), s[i]) - ep.begin();
		int v = std::lower_bound(ep.begin(), ep.end(), t[i]) - ep.begin();
		g[u].push_back(v);
		h[v].push_back(u);
		din[v]++;
		dou[u]++;
	}
	for (int i = 0; i < (int) ep.size() - 1; i++) {
		if (din[i] < dou[i]) {
			return 1;
		}
		if (din[i] > dou[i]) {
			g[i].push_back(i + 1);
			h[i + 1].push_back(i);
			din[i + 1] += din[i] - dou[i];
			dou[i] += din[i] - dou[i];
		}
	}
	auto dfs = [&] (auto&& self, int node, const std::vector <std::vector <int>>& gg, std::vector <bool>& vis) -> int {
		int r = 1;
		vis[node] = true;
		for (int x : gg[node]) {
			if (!vis[x]) {
				r += self(self, x, gg, vis);
			}
		}
		return r;
	};
	std::vector <bool> vis1(ep.size(), false);
	std::vector <bool> vis2(ep.size(), false);
	if (dfs(dfs, 0, g, vis1) < (int) ep.size() || dfs(dfs, 0, h, vis2) < (int) ep.size()) {
		return 1;
	}
	return 0;
}
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