Cod sursa(job #1758034)

Utilizator andrei_uAndrei andrei_u Data 16 septembrie 2016 12:34:50
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <fstream>
#include <vector>

using namespace std;
ofstream fout("bfs.out");
ifstream fin("bfs.in");

vector <int> v[100001];



int n,m,s,x,y,viz[100005];

int bfs(int x)
{
    int i,k=0,j;

    int q[100001]={0};


    q[1]=x;
    k++;
    viz[x]=-1;

    for(i=1;i<=k;i++)
    {
        for(j=0;j<v[q[i]].size();j++)
        {
            if(viz[v[q[i]][j]]==0)
            {
                q[++k]=v[q[i]][j];
                if(viz[q[i]]!=-1) viz[q[k]]=viz[q[i]]+1;

                else viz[q[k]]=viz[q[i]]+2;
            }
        }


    }
}

int main()
{
    fin>>n>>m>>s;

    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;

        v[x].push_back(y);
    }

    bfs(s);

    for(int i=1;i<=n;i++)
    {
        if((viz[i]==0)&&(i!=s))
        {
            fout<<-1<<' ';
        }

        else if(i==s)
        {
            fout<<0<<' ';
        }

        else
        {
            fout<<viz[i]<<' ';
        }
    }

    return 0;
}