Submission #432856

#	Time	Username	Problem	Language	Result	Execution time	Memory
432856		Enkognit	Stations (IOI20_stations)	C++14	0 / 100	3057 ms	2097156 KiB

stations

#include <bits/stdc++.h>
#include "stations.h"
#include <vector>
#define ll long long
#define mp make_pair
#define pb push_back
#define fi first
#define se second

using namespace std;

vector<ll> c[1005];
ll T;
ll in[1005], out[1005], pp[1005];

void dfs(int h,int p=-1)
{
    pp[h]=p;

    in[h]=++T;

    for (int i = 0; i < c[h].size(); i++)
        if (c[h][i]!=p)
        {
            dfs(c[h][i], h);
        }

    out[h]=++T;
}

bool is_ancestor(int x,int y)
{
    return in[x]<=in[y] && out[x]>=out[y];
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	std::vector<int> labels(n);
	for (int i = 0; i < n; i++) {
		labels[i] = i;
	}

	for (int i = 0; i < n-1; i++)
    {
        c[u[i]].pb(v[i]);
        c[v[i]].pb(u[i]);
    }

    dfs(0);

	return labels;
}

int find_next_station(int s, int t, std::vector<int> cc)
{
    if (!is_ancestor(s, t)) return pp[s];
    for (int i = 0; i < c[s].size(); i++)
        if (is_ancestor(c[s][i], t) && pp[s]!=c[s][i]) return c[s][i];
}

Compilation message (stderr)

stations.cpp: In function 'void dfs(int, int)':
stations.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     for (int i = 0; i < c[h].size(); i++)
      |                     ~~^~~~~~~~~~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:56:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     for (int i = 0; i < c[s].size(); i++)
      |                     ~~^~~~~~~~~~~~~
stations.cpp:58:1: warning: control reaches end of non-void function [-Wreturn-type]
   58 | }
      | ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61