Cod sursa(job #2174894)

Utilizator Victor24Vasiesiu Victor Victor24 Data 16 martie 2018 14:03:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <bits/stdc++.h>
#define MOD 1999999973
using namespace std;

int n, m, s, a, b, pasi[100005], oo = 9999999;

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

vector < int > G[100005];

queue < int > q;

void bfs()
{
    q.push(s);

    int aux;

    for ( int i = 1; i <= n ; i++ )
    {
        pasi[i] = oo;
    }

    pasi[s] = 0;

    while ( !q.empty() )
    {
        aux = q.front();
        q.pop();

        for ( auto i : G[aux] )
        {
            if ( pasi [aux] + 1 < pasi[i] )
            {
                q.push( i );
                pasi[i] = pasi[aux] + 1;
            }
        }

    }

}

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

    for ( int i = 1; i <= m ; i++ )
    {
        f>>a>>b;

        G[a].push_back(b);

    }

    bfs();

    for ( int i = 1; i <= n; i++ )
    {
        if ( i == s )
        {
            g<<0<<" ";
        }
        else
        {
            if ( pasi[i] == oo )
            {
                g<<-1<<" ";
            }
            else
            {
                g<<pasi[i]<<" ";
            }
        }
    }

}