Cod sursa(job #3368573)

Utilizator fran_imbImbrea Francesca fran_imb Data 15 octombrie 2026 08:44:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.95 kb
#include<bits/stdc++.h>

using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
/// parcurgere bfs graf neorientat

const int NMAX=1e5;
const int INF = 1e9;
vector<int> L[NMAX+1];
int d[NMAX+1];
int n,m,s;
void bfs(int sursa) ///O(n+m)
{
    for(int i=1;i<=n;i++)
        d[i]=INF;
    d[sursa]=0;
    queue<int> q;
    q.push(sursa);
    while(!q.empty())
    {
        int node=q.front();
        q.pop();
        for(auto vec: L[node])
        {
            if(d[vec]>d[node]+1)
            {
                d[vec]=d[node]+1;
                q.push(vec);
            }
        }
    }


}
int main()
{

    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        L[x].push_back(y);

    }
    bfs(s);
    for(int i=1;i<=n;i++)
        if(d[i]==INF)
        fout<<-1<<" ";
    else
        fout<<d[i]<<" ";

    fin.close();
    fout.close();
    return 0;
}