Cod sursa(job #2576659)

Utilizator AlexAlAxAxelAlAx AlAx AlexAlAxAxel Data 6 martie 2020 21:29:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.95 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");

const int nlim=100005;
int n,m,k;
int dist[nlim];
vector <int> muchii[nlim];
queue <int> coada;

void BFS()
{
    int nod,vecin;
    while(!coada.empty())
    {
        nod=coada.front();
        coada.pop();
        for(int i=0;i<muchii[nod].size();i++)
        {
            vecin=muchii[nod][i];
            if(dist[vecin]==0 && vecin!=k)
            {
                dist[vecin]=dist[nod]+1;
                coada.push(vecin);
            }
        }
    }
}

void citire()
{
    f>>n>>m>>k;
    int x,y;
    for(int i=1;i<=m;i++)
    {
        f>>x>>y;
        muchii[x].push_back(y);
    }
}

int main()
{
    citire();
    coada.push(k);
    dist[k]=0;
    BFS();
    for(int i=1;i<=n;i++)
        if(dist[i]==0 && i!=k)
            g<<"-1 ";
        else g<<dist[i]<<" ";
    return 0;
}