Cod sursa(job #1843240)

Utilizator GoogalAbabei Daniel Googal Data 8 ianuarie 2017 14:44:07
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>
#include <vector>
#include <queue>
#define nmax 100001

using namespace std;

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

vector <int> a[nmax];

queue < int > coada;

int n,m,s,v[nmax];
bool viz[nmax];

void BFS(int x)
{
    int i;
    viz[x]=1;
    coada.push(x);
    while(!coada.empty())
    {
        x=coada.front();
        coada.pop();
        for(i=0;i<a[x].size();i++)
        {
            if(!viz[a[x][i]])
            {
                viz[a[x][i]]=1;
                v[a[x][i]]=v[x]+1;
                coada.push(a[x][i]);
            }
        }
    }
}

inline void read()
{
    int i,x,y;
    fin>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        a[x].push_back(y);
    }
    fin.close();
}

inline void write()
{
    for(int i=1;i<=n;i++)
    {
        if(i!=s && !v[i])
            fout<<"-1 ";
        else
            fout<<v[i]<<' ';
    }
    fout.close();
}

int main()
{
    read();
    BFS(s);
    write();
    return 0;
}