Cod sursa(job #583337)

Utilizator stef93Stefan Gilca stef93 Data 19 aprilie 2011 18:42:04
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

vector <int> g[100003];
queue <int> q;
int n,m,s;
bool u[100003];
int dist[100003];

int main()
{
    int x,y,i,nod;
    ifstream in("bfs.in");
    in>>n>>m>>s;
    for(;m;--m)
    {
        in>>x>>y;
        g[x].push_back(y);
    }
    in.close();
    q.push(s);
    u[s]=1;
    while(!q.empty())
    {
        nod=q.front();
        for(i=0;i<g[nod].size();++i)
        if(!u[g[nod][i]])
        {
            q.push(g[nod][i]);
            dist[g[nod][i]]=dist[nod]+1;
            u[g[nod][i]]=1;
        }
        q.pop();
    }
    ofstream out("bfs.out");
    for(i=1;i<=n;i++)
    if(i==s)out<<0<<' ';
    else
    if(dist[i]>0)out<<dist[i]<<' ';
    else out<<-1<<' ';
    out<<'\n';
    out.close();
    return 0;
}