Cod sursa(job #2627680)

Utilizator DariusGhercaDarius Gherca DariusGherca Data 11 iunie 2020 18:43:10
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.84 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
const int N=1e5+1;
const int M=1e6+1;
int vf[M],urm[M],lst[N],q[N],d[N],n,nr=0,m,s,st,dr=-1;
void adauga(int x,int y)
{
    vf[++nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}
void bfs(int x0)
{
    for(int i=1;i<=n;i++)
    d[i]=-1;
    d[x0]=0;
    q[++dr]=x0;
    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)
            {
                d[y]=1+d[x];
                q[++dr]=y;
            }
        }
    }
}
int main()
{
    f>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        adauga(x,y);
    }
    bfs(s);
    for(int i=1;i<=n;i++)
    g<<d[i]<<" ";
    return 0;
}