Cod sursa(job #2418120)

Utilizator ela_topaTopa Elena ela_topa Data 3 mai 2019 17:59:48
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <string.h>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

constexpr int NX = 100010;
int n, m, s, cost[NX];
vector <int> V[NX];
queue <int> Q;

void bfs(int nod)
{
    memset(cost, -1, sizeof(cost)); //setez toate costurile -1(nevizitate)
    Q.push(nod); //bag start ul
    cost[nod] = 0;

    while(!Q.empty())
    {
        int nodCurent = Q.front();
        Q.pop();
        for(int i=0; i<V[nodCurent].size(); ++i)
        {
            if(cost[V[nodCurent][i]] == -1)
            {
                Q.push(V[nodCurent][i]);
                cost[V[nodCurent][i]] = cost[nodCurent] + 1;
            }
        }
    }
}

int main()
{
    fin>>n>>m>>s; //citesc nodurile, muchiile si vf. de start
    int x, y;
    for(int i=1; i<=m; ++i)
    {
        fin>>x>>y;
        V[x].push_back(y); //le bag pe muchii in lista de vecini
    }

    bfs(s);

    for(int i=1; i<=n; ++i) //afisez costurile
        fout<<cost[i]<<" ";

    return 0;
}