Submission #431590

#	Time	Username	Problem	Language	Result	Execution time	Memory
431590		dreezy	Stations (IOI20_stations)	C++17	0 / 100	865 ms	676 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pb push_back
#define pi pair<int,int>

vector<int> labels;
vector<vector<int>> graph;

vector<pi> ord;
int cnt = 0;
void dfs1(int n,int p){//calc sizes
	ord[n].first = cnt++;
	for(int adj : graph[n])
	{
		if(adj == p) continue;
		dfs1(adj, n);
	}
	ord[n].second = cnt++;
}



void name_subtree(int n, int p, bool first){
	if(first)
		labels[n] = ord[n].first;
	else
		labels[n] = ord[n].second;
	for(int adj : graph[n]){
		if(adj == p)
		continue;
		name_subtree(adj, n, !first);
	}
}


vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	cnt = 0;
	ord.clear();
	labels.clear();
	graph.clear();
	ord.assign(n, {0,0});
	labels.assign(n, 0);
	graph.assign( n, vector<int>());
	for (int i = 0; i < n - 1; i++) {
		graph[u[i]].pb(v[i]);
		graph[v[i]].pb(u[i]);
	}
	

	dfs1(0,-1);
	int root = 0;
	//for(int i =0; i<n; i++) cout <<i<<": "<< ord[i].first<<", "<<ord[i].second<<endl;
	
	name_subtree(root, -1, 1);
	//for(int i =0; i<n; i++) cout <<i<<": "<< labels[i]<<endl;
	
	return labels;
}

int find_next_station(int s, int t, vector<int> c) {
	if(c.size() == 1) return c[0];
	
	bool isfirst = c[0] > s;

	
	if(isfirst){
		if(t < s) return c[c.size() - 1];
		for(int adj : c){
			if(t <= adj) return adj;
		}
		return c[c.size()-1] ;
	}
	else{
		//if( t > s) return c[0];
		//reverse(c.begin(), c.end());
		for(int adj : c)
			if(t <= adj)
				return adj;
		return c[0];
	}
	
	return c[0];
}


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