Cod sursa(job #2509508)

Utilizator AndreeaGherghescuAndreea Gherghescu AndreeaGherghescu Data 14 decembrie 2019 12:04:45
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <iostream>
#include <fstream>

using namespace std;

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

const int N=100002;
const int M=1000002;
int nr,lst[N],urm[2*M],vf[2*M],d[N],q[N],n,m;

void adauga (int x, int y)
{
    vf[++nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}
void bfs (int xx)
{
    int st,dr;
    for (int i=1;i<=n;i++)
        d[i]=-1;
    st=0;
    dr=-1;
    q[++dr]=xx;
    d[xx]=0;
    while (st<=dr)
    {
        int x=q[st++];
        for (int p=lst[x];p!=0;p=urm[p])
        {
            int y=vf[p];
            if (d[y]==-1)
            {
                q[++dr]=y;
                d[y]=d[x]+1;
            }
        }
    }
}

int main()
{
    int s,x,y;
    in>>n>>m>>s;
    for (int i=1;i<=m;i++)
    {
        in>>x>>y;
        adauga (x,y);
    }
    bfs (s);
    for (int i=1;i<=n;i++)
        out<<d[i]<<' ';
    return 0;
}