Submission #635353

#	Time	Username	Problem	Language	Result	Execution time	Memory
635353		Bruteforceman	Roller Coaster Railroad (IOI16_railroad)	C++17	64 / 100	456 ms	65672 KiB

railroad

    #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;
    }

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 0 / 36