Submission #838288

#	Time	Username	Problem	Language	Result	Execution time	Memory
838288		puppy	Stations (IOI20_stations)	C++17	100 / 100	678 ms	796 KiB

stations

#include "stations.h"
#include <vector>
#include <functional>
#include <algorithm>
#include <iostream>
using namespace std;

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	vector<vector<int>> adj(n);
	for (int i = 0; i < n-1; i++) {
		adj[u[i]].push_back(v[i]);
		adj[v[i]].push_back(u[i]);
	}
	vector<int> id(n);
	int ord = 0;
	function<void(int, int, int)> dfs = [&](int v, int p, int depth)
	{
		if (depth % 2 == 0) id[v] = ord++;
		for (int i:adj[v]) {
			if (i != p) dfs(i, v, depth + 1);
		}
		if (depth % 2 == 1) id[v] = ord++;
	};
	dfs(0, -1, 0);
	return id;
}

int find_next_station(int s, int t, std::vector<int> c) {
	int parity = s > c[0];
	sort(c.begin(), c.end());
	if (s) {
		if (parity == 0) {
			if (t < s || c[c.size()-2] < t || c.size() == 1) return c.back();
		}
		else {
			if (t < c[1] || s < t || c.size() == 1) return c[0];
		}
	}
	if (parity == 0) {
		for (int i = 0; i < (int)c.size(); i++) {
			if (t <= c[i]) return c[i];
		}
	}
	else {
		for (int i = (int)c.size() - 1; i >= 0; i--) {
			if (t >= c[i]) return c[i];
		}
	}
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:49:1: warning: control reaches end of non-void function [-Wreturn-type]
   49 | }
      | ^

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