Submission #1205408

#	Time	Username	Problem	Language	Result	Execution time	Memory
1205408		bangan	Stations (IOI20_stations)	C++20	10 / 100	310 ms	564 KiB

stations

#include "stations.h"
#include <vector>
#include <bits/stdc++.h>

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	std::vector<std::vector<int>> adj(n);
	for (int i = 0; i < n - 1; i++) {
		adj[v[i]].push_back(u[i]);
		adj[u[i]].push_back(v[i]);
	}

	int timer = 0;
	std::vector<int> st(n), ft(n), dep(n);
	auto dfs = [&](auto self, int v, int f) -> void {
		st[v] = timer++;
		for (int u : adj[v]) {
			if (u != f) {
				dep[u] = dep[v] ^ 1;
				self(self, u, v);
			}
		}
		ft[v] = timer;
	};
	dfs(dfs, 0, 0);

	std::vector<int> id(n);
	for (int i = 0; i < n; i++) {
		id[i] = st[i] * 1000 + ft[i];
	}
	return id;
}

int find_next_station(int s, int t, std::vector<int> c) {
	int st_s = s / 1000, ft_s = s % 1000;
	int st_t = t / 1000, ft_t = t % 1000;
	std::vector<int> st(c.size()), ft(c.size());
	for (int i = 0; i < c.size(); i++) {
		st[i] = c[i] / 1000, ft[i] = c[i] % 1000;
	}

	for (int i = 0; i < c.size(); i++) {
		if (st_s <= st[i] && st[i] < ft_s && st[i] <= st_t && st_t < ft[i]) {
			return c[i];
		}
	}
	for (int i = 0; i < c.size(); i++) {
		if (st_s > st[i] || st[i] >= ft_s) {
			return c[i];
		}
	}
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:51:1: warning: control reaches end of non-void function [-Wreturn-type]
   51 | }
      | ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 10 / 10
• Subtask 5: 0 / 61