Submission #305155

#	Time	Username	Problem	Language	Result	Execution time	Memory
305155		Temmie	Stations (IOI20_stations)	C++17	100 / 100	1194 ms	1056 KiB

stations

#include <bits/stdc++.h>

struct Node {
	std::vector <int> nei;
	int d, a, b;
	Node() : d(0), a(0), b(0) { }
};

struct Triplet {
	int x, y, z;
	Triplet(int X = 0, int Y = 0, int Z = 0) : x(X), y(Y), z(Z) { }
	bool operator<(const Triplet& other) const {
		if (x == other.x) return y > other.y;
		return x < other.x;
	}
};

int cnt;
void dfs(std::vector <Node>& g, int node = 0, int par = -1) {
	g[node].a = cnt++;
	g[node].d = par == -1 ? 0 : g[par].d + 1;
	for (int x : g[node].nei) if (x != par) dfs(g, x, node);
	g[node].b = cnt - 1;
}

std::vector <int> label(int n, int k, std::vector <int> u, std::vector <int> v) {
	
	cnt = 0;
	std::vector <int> r(n);
	std::vector <Node> g(n);
	for (int i = 0; i < n - 1; i++) {
		g[u[i]].nei.push_back(v[i]);
		g[v[i]].nei.push_back(u[i]);
	}
	dfs(g);
	std::vector <Triplet> tr(n);
	for (int i = 0; i < n; i++) tr[i] = Triplet(g[i].d & 1 ? g[i].b : g[i].a, g[i].d, i);
	std::sort(tr.begin(), tr.end());
	for (int i = 0; i < n; i++) r[tr[i].z] = i;
	return r;
	
}

int find_next_station(int s, int t, std::vector <int> c) {
	if (!(c.size() - 1)) return c.front();
	if (!s) for (int x : c) if (t <= x) return x;
	if (s < c.front()) {
		if (!(s <= t && t <= c[c.size() - 2])) return c.back();
		for (int x : c) if (t <= x) return x;
	}
	if (!(t <= s && c[1] <= t)) return c.front();
	for (int i = (int)c.size() - 1; i >= 0; i--) if (c[i] <= t) return c[i];
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61