Submission #305105

#	Time	Username	Problem	Language	Result	Execution time	Memory
305105		Bench0310	Stations (IOI20_stations)	C++17	100 / 100	1166 ms	1120 KiB

stations

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

using namespace std;
typedef long long ll;

const int N=1000;
vector<int> v[N];
vector<int> depth(N,0);
vector<int> tin(N,0);
vector<int> tout(N,0);
int tcnt=0;

void dfs(int a,int p=-1)
{
    if(p!=-1) depth[a]=depth[p]+1;
    tin[a]=tcnt++;
    for(int to:v[a])
    {
        if(to==p) continue;
        dfs(to,a);
    }
    tout[a]=tcnt-1;
}

vector<int> label(int n,int k,vector<int> a,vector<int> b)
{
    for(int i=0;i<n;i++)
    {
        v[i].clear();
        depth[i]=tin[i]=tout[i]=0;
    }
    tcnt=0;
    for(int i=0;i<n-1;i++)
    {
        v[a[i]].push_back(b[i]);
        v[b[i]].push_back(a[i]);
    }
    dfs(0);
    vector<int> res(n,0);
    vector<array<int,3>> z(n);
    for(int i=0;i<n;i++) z[i]={((depth[i]%2)==0?tin[i]:tout[i]),depth[i],i};
    sort(z.begin(),z.end(),[](array<int,3> x,array<int,3> y)->bool{return (x[0]<y[0]||(x[0]==y[0]&&x[1]>y[1]));});
    for(int i=0;i<n;i++) res[z[i][2]]=i;
    return res;
}

int find_next_station(int s,int t,vector<int> c)
{
    if(c.size()==1) return c[0];
    if(s==0)
    {
        for(int a:c) if(t<=a) return a;
    }
    else if(s<c[0]) //tin
    {
        if(!(s<=t&&t<=c[c.size()-2])) return c.back();
        for(int a:c) if(t<=a) return a;
    }
    else //tout
    {
        if(!(c[1]<=t&&t<=s)) return c[0];
        reverse(c.begin(),c.end());
        for(int a:c) if(a<=t) return a;
    }
}

//int main()
//{
//    ios::sync_with_stdio(0);
//    cin.tie(0);
//    
//    return 0;
//}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:66:1: warning: control reaches end of non-void function [-Wreturn-type]
   66 | }
      | ^

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