Submission #349795

#	Time	Username	Problem	Language	Result	Execution time	Memory
349795		blue	Stations (IOI20_stations)	C++17	100 / 100	989 ms	1232 KiB

stations

#include "stations.h"
#include <iostream>
#include <vector>
using namespace std;
 
vector<int> edge[1000];
vector<int> visit(1000, 0);
vector<int> L;
 
int dfs(int u, int a, bool flag) //vertex, minimum label, left/right?     return largest unused label
{
    visit[u] = 1;
 
    if(flag == 0)
    {
        L[u] = a;
        a++;
    }
 
    for(int v: edge[u])
    {
        if(visit[v]) continue;
        a = dfs(v, a, !flag);
    }
 
    if(flag == 1)
    {
        L[u] = a;
        a++;
    }
 
    return a;
}
 
vector<int> label(int n, int k, vector<int> u, vector<int> v)
{
    for(int i = 0; i < n; i++) 
    {
      edge[i].clear();
      visit[i] = 0;
    }
  
  
    for(int j = 0; j < n-1; j++)
    {
        edge[u[j]].push_back(v[j]);
        edge[v[j]].push_back(u[j]);
    }
 
    L = vector<int>(n, -1);
 
    dfs(0, 0, 0);
 
    return L;
}
 
int find_next_station(int s, int t, vector<int> c)
{
    if(s < c[0]) // s is left label
    {
        if(t < s) return c[c.size()-1];
        for(int i = 0; i < c.size(); i++) if(t <= c[i]) return c[i];
        return c[c.size()-1];
    }
    else // s is right label
    {
        if(t > s) return c[0];
        for(int i = c.size()-1; i >= 0; i--) if(t >= c[i]) return c[i];
        return c[0];
    }
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:62:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         for(int i = 0; i < c.size(); i++) if(t <= c[i]) return c[i];
      |                        ~~^~~~~~~~~~

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