Cod sursa(job #1708467)

Utilizator radiogard1999Dragoi Andrei radiogard1999 Data 27 mai 2016 09:58:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <bits/stdc++.h>

using namespace std;

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

vector <int> a[100003];
int n,m,v[100003],d[100003],s;
queue <int> q;
void Citire()
{
    int i,x,y;
    fin>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
    }
    fin.close();
}

void BFS(int s)
{
    q.push(s);
    v[s]=1;
    int i,j,k;
    while(!q.empty())
    {
        k=q.front();
        q.pop();
        for(i=0;i<a[k].size();i++)
        {
            j=a[k][i];
            if(v[j]==0)
            {
                v[j]=1;
                d[j]=d[k]+1;
                q.push(j);
            }
        }
    }
    for(i=1;i<=n;i++) if(d[i]==0 && i!=s)fout<<"-1 ";
        else fout<<d[i]<<" ";
    fout<<"\n";
    fout.close();
}

int main()
{
    Citire();
    BFS(s);
    return 0;
}