Cod sursa(job #3154118)

Utilizator PieleVoinescu David Piele Data 3 octombrie 2023 12:39:24
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.74 kb
// AlgFund.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

const int NMAX = 100001;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

int dist[NMAX];
bool viz[NMAX];
vector<int> G[NMAX+1];
int n, m, s;
//int Mat[NMAX+1][NMAX+1];
/*
void Citire_Matrice()
{
    fin >> n >> m;
    int x, y;
    for (int i = 0; i < m; ++i)
    {
        fin >> x >> y;
        Mat[x][y] = 1;
        Mat[y][x] = 1;
    }
}
void Afisare_Matrice()
{
    for(int i=1;i<=n;++i){
        for(int j=1;j<=n;++j)
        cout<<Mat[i][j]<<" ";
    cout<<'\n';}
}

*/
void Citire_Lista()
{
    fin >> n >> m >> s;
    int x, y;
    for(int i = 0; i < m; ++i)
    {
        fin >> x >> y;
        G[x].push_back(y);
    }
}



void Afisare_Lista()
{
    for(int i=1;i<=n;++i)
    {
        cout<<i<<": ";
        for (auto x :G[i])
            cout<<x<<" ";
        cout<<'\n';
    }
}

void bfs(int start)
{
    queue<int> Q;
    viz[start]=1;
    dist[start]=0;
    Q.push(start);
    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();
        for(auto x : G[nod])
        {

            if(!viz[x]){
            dist[x]=dist[nod]+1;
            Q.push(x);
            viz[x]=1;
            }
        }
    }
}

void Afisare_Dist()
{
    for(int i=1; i<=n;++i){
        if(i==s)
        fout<<"0 ";
    else if (dist[i]==0)
        fout<<"-1 ";
    else
        fout<<dist[i]<<" ";

    }
}

int main()
{
    //Citire_Matrice();
    //Afisare_Matrice();
    Citire_Lista();
    //Afisare_Lista();
    bfs(s);
    Afisare_Dist();
    return 0;
}