Cod sursa(job #2158831)

Utilizator timar_andreiTimar Andrei timar_andrei Data 10 martie 2018 16:39:23
Problema Diametrul unui arbore Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("darb.in");
ofstream fout("darb.out");

vector<int> G[100002];
queue<int> Q;
int N;
int D[100002];
int M;

void Read()
{
    fin>>N;
    for(int i=1;i<=N-1;i++)
    {
        int x,y;
        fin>>x>>y;

        G[x].push_back(y);
        G[y].push_back(x);
    }
}
void BFS(int s)
{
    for(int i=1;i<=N;i++)
        D[i] = -1;
    D[s] = 0;
    Q.push(s);

    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();

        for(int i=0;i<G[nod].size();i++)
        {
            int vecin = G[nod][i];
            if (D[vecin] == -1)
            {
                D[vecin] = D[nod] + 1;
                Q.push(vecin);
            }
        }
        if (M < D[nod])
            M = D[nod];
    }

}

int main()
{
    Read();

    for(int i=1;i<=N;i++)
    {
        BFS(i);
    }
    fout<<M+1;
    return 0;
}