Submission #718276

#	Time	Username	Problem	Language	Result	Execution time	Memory
718276		duchuy297	Stations (IOI20_stations)	C++17	100 / 100	955 ms	832 KiB

stations

#include "stations.h"
#include <vector>
#include<bits/stdc++.h>
using namespace std;
const int N = 1005;
vector<int> adj[N];
int cnt;
vector<int> res;
int ti[N],to[N],lv[N];
void dfs (int u, int p) {
	ti[u] = cnt++;
	for (auto v : adj[u]) {
		if (v == p) continue;
		lv[v] = (lv[u] ^ 1);
		dfs(v,u);
	}
	to[u] = cnt++;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	cnt = 0;
	res.resize(n);
	for (int i=0; i<n; i++) adj[i].clear();
	for (int i=0; i<n-1; i++) {
		adj[u[i]].push_back(v[i]);
		adj[v[i]].push_back(u[i]);
	}
	dfs (0,0);
	vector<pair<int,int> > p;
	for (int i=0; i<n; i++) {
		if (lv[i] % 2) p.push_back({ti[i],i});
		else p.push_back({to[i],i});
	}
	sort (p.begin(),p.end());
	int g = 0;
	for (auto u : p) res[u.second] = g++;
	return res;
}
int find_next_station(int s, int t, vector<int> c) {
	sort (c.begin(),c.end());
	if (s < c[0]) { // in
		if (t < s) return c.back(); // father
		// ti[s] >= t
		for (int i=0; i<(int)c.size()-1; i++) {
			if (c[i] >= t)  return c[i];
		}
		return c.back();
	}
	else { // out
		if (t > s) return c[0]; // father
		// to[s] >= t
		for (int i=(int) c.size() - 1; i>=1; i--) {
			if (c[i] <= t) return c[i];
		}
		return c[0];
	}
}

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