Cod sursa(job #2549719)

Utilizator daru06Daria Culac daru06 Data 17 februarie 2020 22:18:00
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <fstream>
#include <vector>
#define NMAX 100005

using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

int n,m,s;
int viz[NMAX];
int c[NMAX];
int p,u;

vector <int> A[NMAX];

void bfs(int nod)
{
    p=u=1;
    viz[nod]=1;
    c[p]=nod;
    while(p<=u)
    {
        int x=c[p];
        p++;
        vector <int> ::iterator it;
        for(it=A[x].begin();it!=A[x].end();it++)
            if(viz[*it]==0)
        {
            c[++u]=*it;
            viz[*it]=1+viz[x];
        }
    }
}

int main()
{
    f>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        A[x].push_back(y);

    }
    bfs(s);
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
            g<<-1<<" ";
        else
            g<<viz[i]-1<<" ";
    f.close();
    g.close();
    return 0;
}