Submission #611104

#	Time	Username	Problem	Language	Result	Execution time	Memory
611104		Temmie	Roller Coaster Railroad (IOI16_railroad)	C++17	34 / 100	391 ms	28364 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);
}

struct MS {
	std::map <std::pair <int, int>, int> mp;
	inline void insert(std::pair <int, int> p) {
		mp[p]++;
	}
	inline void erase(std::pair <int, int> p) {
		auto it = mp.find(p);
		if (!(--it->second)) {
			mp.erase(it);
		}
	}
	inline std::pair <int, int> begin() {
		return mp.begin()->first;
	}
};

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);
	}
	MS st, ts;
	for (int i = 0; i < n; i++) {
		st.insert({ s[i], t[i] });
		st.insert({ t[i], s[i] });
	}
	bool fl = false;
	for (int i = 0; i < n - 1; i++) {
		auto p = st.begin();
		st.erase(p);
		//std::cerr << i << ": " << p.first << ", " << p.second << std::endl;
		ts.erase({ p.second, p.first });
		std::pair <int, int> pp;
		if ((pp = ts.begin()).first > p.first) {
			if (fl) {
				return 1;
			}
			p.first = 1 << 30;
			st.erase({ pp.second, pp.first });
			ts.erase(pp);
			st.insert(p);
			ts.insert({ p.second, p.first });
			fl = true;
			continue;
		}
		p.first = p.second;
		st.erase({ pp.second, pp.first });
		ts.erase(pp);
		st.insert(p);
		ts.insert({ p.second, p.first });
	}
	return 0;
}

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