Submission #791176

#	Time	Username	Problem	Language	Result	Execution time	Memory
791176		Pablo_No	Stations (IOI20_stations)	C++17	0 / 100	331 ms	592 KiB

stations

#include "stations.h"
#include <algorithm>
#include <vector>

using namespace std;

vector<int> col;
vector<vector<int>> g;

int dfsfd(int v, int p, int d)
{
	if(g[v].size() == d)
	{
		return v;
	}

	for(int u : g[v]) if(u != p)
	{
		int x = dfsfd(u, v, d);
		if(x != -1)
		{
			return x;
		}
	}

	return -1;
}

void dfs(int v, int p, int d)
{
	col[v] = d-1;
	int ns = 0;
	for(int u : g[v]) if(u != p)
	{
		dfs(u, v, 2*d+ns);
		ns++;
	}
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v)
{
	g.assign(n, vector<int>(0));
	col.resize(n);
	for(int i = 0; i < n-1; i++)
	{
		g[u[i]].push_back(v[i]);
		g[v[i]].push_back(u[i]);
	}
	dfs(dfsfd(1, -1, 2), -1, 1);

	return col;
}

int find_next_station(int s, int t, std::vector<int> c) {
	sort(c.begin(), c.end());
	int ts = s+1;
	int tt = t+1;
	int t1 = 2*ts;
	int t2 = 2*ts+1;
	while(tt && tt != t1 && tt != t2)
	{
		tt /= 2;
	}
	if(tt == t1)
		return t1-1;
	if(tt == t2)
		return t2-1;
	return ts/2-1;
}

Compilation message (stderr)

stations.cpp: In function 'int dfsfd(int, int, int)':
stations.cpp:12:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   12 |  if(g[v].size() == d)
      |     ~~~~~~~~~~~~^~~~

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