Cod sursa(job #1334967)

Utilizator t_@lexAlexandru Toma t_@lex Data 4 februarie 2015 20:29:04
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.88 kb
# include <fstream>
# include <vector>
# include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,i,s,b[100001];
vector<int> a[100001];
queue<int> q;
void read()
{
    int x,y;
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
         {
          f>>x>>y;
          a[x].push_back(y);
         }
}
void BFS()
{
    int x,d;
    q.push(s);
    b[s]=1;
    while(!q.empty())
            {
             x=q.front();
             q.pop();
             d=a[x].size();
             for(i=0;i<d;i++)
                 if(!b[a[x][i]])
                    {
                     b[a[x][i]]=b[x]+1;
                     q.push(a[x][i]);
                    }

            }
}
void write()
{
    for(i=1;i<=n;i++)
        g<<b[i]-1<<" ";
}
int main()
{
    read();
    BFS();
    write();
    f.close();
    g.close();
    return 0;
}