Cod sursa(job #1354291)

Utilizator cosminionutCosmin Ionut cosminionut Data 21 februarie 2015 19:03:43
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <fstream>
using namespace std;

ofstream g("bfs.out");

int N, M, S, x, y, dist[100001], coada[100001], prim, ultim;
struct nod{int info; nod *urm;} *p, *li[100001];
bool viz[100001];

void push(nod *&li, int informatie)
{
    p=new nod();
    p->info=informatie;
    p->urm=li;
    li=p;
}

void pop(nod *&li)
{
    p=li;
    li=li->urm;
    delete(p);
}

void BFS()
{
    int A;
    prim=ultim=1;
    coada[prim]=S;
    while(prim<=ultim)
    {
        A=coada[prim];
        viz[A]=1;
        while(li[A])
        {
            if(!viz[li[A]->info])
            {
                dist[li[A]->info]=dist[A]+1;
                ultim++;
                coada[ultim]=li[A]->info;
            }
            pop(li[A]);
        }
        prim++;
    }
}

int main()
{
    int i;
    FILE *f; f=fopen("bfs.in","r");
    fscanf(f, "%d%d%d", &N, &M, &S);
    for(i=1;i<=M;i++)
    {
        fscanf(f, "%d%d", &x, &y);
        push(li[x], y);
    }
    BFS();
    for(i=1;i<S;i++)
        if(dist[i]==0)  g<<"-1 ";
        else            g<<dist[i]<<" ";
    g<<"0 ";
    for(i=S+1;i<=N;i++)
        if(dist[i]==0)  g<<"-1 ";
        else            g<<dist[i]<<" ";
    return 0;
}