Submission #400323

#	Time	Username	Problem	Language	Result	Execution time	Memory
400323		REALITYNB	Stations (IOI20_stations)	C++14	100 / 100	1156 ms	992 KiB

stations

#include <bits/stdc++.h> 
#include "stations.h"
using namespace std; 
vector<int> label(int n ,int l , vector<int> u , vector<int> v){
    vector<int> ans(n) ; 
    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]); 
    }
    function<vector<int>(int,int,int)> dfs = [&](int a ,int p , int lvl){
        vector<int> ans ; 
        if(lvl)
            ans.push_back(a) ; 
        for(int x : adj[a]){
            if(x!=p){
                vector<int> res = dfs(x,a,lvl^1) ; 
                for(int x :res) ans.push_back(x) ;
            }
        }
        if(lvl==0) ans.push_back(a) ; 
        return ans ; 
    }; 
    vector<int> res  = dfs(0,-1,1) ; 
    for(int i=0;i<n;i++) ans[res[i]]=i ; 
    return ans ; 
}
int find_next_station(int u , int v , vector<int> ne){
    if(u==0){
        if(u<=v&&v<=ne[0]) return ne[0] ; 
        for(int i=1;i<ne.size();i++) if(ne[i]>=v&&v>ne[i-1]) return ne[i] ; 
    }
    if(u<=ne[0]){
        int dad = ne.back() ; 
        if(u<=v&&v<=ne[0]) return ne[0] ; 
        for(int i=1;i+1<ne.size();i++)
            if(ne[i]>=v&&v>ne[i-1]) return ne[i] ; 
        return dad ; 
    }
    else{
        int dad = ne[0] ;
        if(u>=v&&v>=ne.back()) return ne.back() ;  
        for(int i=(int)(ne.size()-2);i>0;i--)
            if(ne[i+1]>v&&v>=ne[i]) return ne[i] ; 
        return dad ; 
    }
    return 5/0; 
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         for(int i=1;i<ne.size();i++) if(ne[i]>=v&&v>ne[i-1]) return ne[i] ;
      |                     ~^~~~~~~~~~
stations.cpp:36:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for(int i=1;i+1<ne.size();i++)
      |                     ~~~^~~~~~~~~~
stations.cpp:47:13: warning: division by zero [-Wdiv-by-zero]
   47 |     return 5/0;
      |            ~^~

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