Cod sursa(job #829779)

Utilizator enedumitruene dumitru enedumitru Data 5 decembrie 2012 20:39:38
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.76 kb
#include <fstream>
#include <queue>
#include <vector>
#include <cstring>
#define Nmax 100005
using namespace std;
ifstream f("bfs.in"); ofstream g("bfs.out");
int n, m, s;
vector <int> V[Nmax];
queue <int> Q;
bool viz[Nmax];
int nivel[Nmax];
int main()
{   f>>n>>m>>s;
    for(int i=1; i<=m; ++i)
        {   int x,y;
            f>>x>>y; V[x].push_back(y);
        }
    memset(nivel,-1,sizeof(nivel));
    Q.push(s); viz[s]=true; nivel[s]=0;
    while(!Q.empty())
    {   int a=Q.front(); Q.pop();
        vector <int> :: iterator it=V[a].begin(), sf=V[a].end();
        for(; it != sf ; ++it)
            if(!viz[*it]) {viz[*it]=true; nivel[*it]=nivel[a]+1;  Q.push(*it);}
    }
    for(int i=1; i<=n; ++i) g<<nivel[i]<<' ';
    return 0;
}