Cod sursa(job #2456529)

Utilizator LXGALXGA a LXGA Data 14 septembrie 2019 16:02:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.86 kb
#include <fstream>
#include <queue>
#include <vector>
#include <cstring>
using namespace std;
vector<int> v[100001];
queue<int> q;
ifstream cin("bfs.in");
ofstream cout("bfs.out");
int use[100001];
void bfs(int pos)
{
    q.push(pos);
    memset(use,-1,sizeof(use));
    use[pos]=0;

    while(q.size()>0)
    {
        for(int i=0;i<v[q.front()].size();i++)
        {
            if(use[v[q.front()][i]]==-1)
            {
                q.push(v[q.front()][i]);
                use[v[q.front()][i]]=use[q.front()]+1;
            }


        }
        q.pop();
    }
}
int n,m,s;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin>>n>>m>>s;

    int x,y;

    for(int i=1;i<=m;i++)
    {
        cin>>x>>y;
        v[x].push_back(y);
        //v[y].push_back(x);
    }

    bfs(s);

    for(int i=1;i<=n;i++)
        cout<<use[i]<<" ";

    return 0;
}