Cod sursa(job #2652648)

Utilizator tudorbuhniaTudor Buhnia tudorbuhnia Data 25 septembrie 2020 13:36:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
vector<int> v[100005];
queue<int> q;
queue<int> qv;
bool vs[100005];
int vr[100005];
void edge(int x,int y)
{
    v[x].push_back(y);
}
void bfs(int n)
{
    int x;
    for(int i=0;i<v[n].size();i++)
    {
        x=v[n].at(i);
        if(vs[x]==0)
        {
            vs[x]=1;
            q.push(x);
            vr[x]=vr[n]+1;
        }
    }
    if(q.empty()==false)
    {
        x=q.front();
        q.pop();
        bfs(x);
    }
}
int main()
{
    ifstream cin("bfs.in");
    ofstream cout("bfs.out");
    int n,m,s,x,y;
    cin >> n >> m >> s;
    fill_n (vr+1, n, -1);
    for(int i=0;i<m;i++)
    {
        cin >> x >> y;
        if(x!=y)
            edge(x,y);
    }
    vs[s]=1;
    vr[s]=0;
    bfs(s);
    for(int i=1;i<=n;i++)
    {
        if(vs[i]==0)
            cout << -1 << " ";
        else
        {
            cout << vr[i] << " ";
        }
    }
    return 0;
}