Cod sursa(job #2926875)

Utilizator Samoila_AlexandruSamoilaAlexandru Samoila_Alexandru Data 18 octombrie 2022 21:13:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

const int dim=1e5+1;

queue<int> q;
vector<int> g[dim];
bool v[dim];

int n, m, S, x, y, d[dim];

void bfs(int start)
{
    q.push(start);
    v[start]=1;
    while(!q.empty())
    {
        int k=q.front();

        q.pop();

        for(auto& i: g[k])
            if(!v[i])
        {
            v[i]=1;
            d[i]=d[k]+1;
            q.push(i);
        }
    }
}

int main()
{
    fin>>n>>m>>S;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
    }
    fin.close();

    bfs(S);

    for(int i=1; i<=n; i++)
        if(i!=S)
        {
            if(d[i])
                fout<<d[i]<<' ';
            else fout<<-1<<' ';
        }
        else fout<<0<<' ';

    fout.close();

    return 0;
}