Cod sursa(job #613139)

Utilizator predator5047Butiu Alexandru Octavian predator5047 Data 16 septembrie 2011 22:09:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <vector>
#include <fstream>
#include <queue>
using namespace std;
void afisare(int *cost,int &n);
int main()
{
    int n,m,s,x,y,cost[100001];
    vector<int> v [100001];
    vector<int>::iterator it;
    ifstream fin("bfs.in");
    fin>>n>>m>>s;
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    fin.close();
    for(int i=1;i<=n;++i) cost[i]=-1;
    queue<int> q;
    q.push(s); cost[s]=0;
    while(!q.empty())
    {
        int now=q.front();
        for(it=v[now].begin();it<v[now].end();++it)
            if(cost[*it]==-1)
            {
                cost[*it]=cost[now]+1;
                q.push(*it);
            }
        q.pop();
    }
    afisare(cost,n);
    return 0;
}

void afisare(int *cost,int &n)
{
    ofstream fout("bfs.out");
    for(int i=1;i<=n;++i)
        fout<<cost[i]<<" ";
    fout.close();
}