Submission #964634

#	Time	Username	Problem	Language	Result	Execution time	Memory
964634		irmuun	Stations (IOI20_stations)	C++17	100 / 100	591 ms	1644 KiB

stations

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

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const int N=1e3+5;
vector<int>adj[N],tin(N),tout(N),dep(N);
int cur=0;
void dfs(int x,int p){
    tin[x]=cur++;
    for(auto y:adj[x]){
        if(y!=p){
            dep[y]=dep[x]+1;
            dfs(y,x);
        }
    }
    tout[x]=cur++;
}

vector<int>label(int n,int k,vector<int>u,vector<int>v){
    cur=0;
    for(int i=0;i<n;i++){
        adj[i].clear();
    }
    for(int i=0;i<n-1;i++){
        adj[u[i]].pb(v[i]);
        adj[v[i]].pb(u[i]);
    }
    dfs(0,-1);
    vector<int>l(n);
    for(int i=0;i<n;i++){
        if(dep[i]%2==0){
            l[i]=tin[i];
        }
        else{
            l[i]=tout[i];
        }
        l[i]/=2;
    }
    return l;
}
 
int find_next_station(int s,int t,vector<int>c){
    s*=2;
    t*=2;
    for(int i=0;i<c.size();i++) c[i]*=2;
    if(s<c[0]){
        int l=s+1;
        for(int i=0;i<(int)c.size()-1;i++){
            if(l<=t&&t<=c[i]){
                return c[i]/2;
            }
            l=c[i]+1;
        }
        return c.back()/2;
    }
    else{
        int r=s-1;
        for(int i=(int)c.size()-1;i>0;i--){
            if(c[i]<=t&&t<=r){
                return c[i]/2;
            }
            r=c[i]-1;
        }
        return c[0]/2;
    }
    return 0;
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:53:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     for(int i=0;i<c.size();i++) c[i]*=2;
      |                 ~^~~~~~~~~

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