Submission #1234570

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234570		caacrugon	Stations (IOI20_stations)	C++20	100 / 100	303 ms	600 KiB

stations

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

using namespace std;

int cnt=-1;

int dfs(vector<int>&labels,vector<bool>&visited,vector<vector<int>>&adj,int nodo,bool par){
	cnt++;
	visited[nodo]=true;
	if(par){
		labels[nodo]=cnt;
		par=false;
	}else{
		par=true;
	}
	int maxi=0;
	for(int j=0;j<adj[nodo].size();j++){
		if(visited[adj[nodo][j]])continue;
		maxi=max(maxi,dfs(labels,visited,adj,adj[nodo][j],par));
	}
	if(par){
		cnt++;
		labels[nodo]=cnt;
	}
	return labels[nodo];
}

vector<int> compress(vector<int> a){
	vector<int> b=a;
	sort(b.begin(),b.end());
	vector<int> labels(a.size());
	for(int i=0;i<b.size();i++){
		int n=lower_bound(b.begin(),b.end(),a[i])-b.begin();
		labels[i]=n;
	}
	return labels;
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	std::vector<int> labels(n);
	cnt=0;
	for (int i = 0; i < n; i++) {
		labels[i] = i;
	}
	vector<int> indegree(n,0);
	vector<vector<int>> adj(n,vector<int>(0,0));
	for(int i=0;i<u.size();i++){
		adj[u[i]].push_back(v[i]);
		adj[v[i]].push_back(u[i]);
		indegree[u[i]]++;
		indegree[v[i]]++;
	}
	stack<int> st;
	for(int i=0;i<n;i++){
		if(indegree[i]==1){
			st.push(i);
			break;
		}
	}
	vector<bool> visited(n,false);
	dfs(labels,visited,adj,st.top(),1);
	labels=compress(labels);
	return labels;
}

int find_next_station(int s, int t, std::vector<int> c) {
	if(s>c[c.size()-1]){
		if(t>s || t<=c[0])return c[0];
		int nans=s;
		for(int i=c.size()-1;i>=-1;i--){
			if(t>=nans && t<s)return c[i+1];
			nans=c[i];
		}
	}else{
		if(s>t || t>=c[c.size()-1])return c[c.size()-1];
		int nans=0;
		for(int i=0;i<c.size();i++){
			if(t>nans && t<=c[i])return c[i];
			nans=c[i];
		}
	}
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:84:1: warning: control reaches end of non-void function [-Wreturn-type]
   84 | }
      | ^

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