Cod sursa(job #628844)

Utilizator cat_red20Vasile Ioana cat_red20 Data 2 noiembrie 2011 11:13:35
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <stdio.h>
#include <queue>
#include <vector>
using namespace std;
vector<int> v[100001];
queue <int> q;
FILE *fin,*fout;
int n,m,s,tata[100001],d[100001];
void citire()
{
    int x,y;
    fin=fopen("bfs.in","r");
    fscanf(fin,"%d %d %d",&n,&m,&s);
    for(int i=0;i<m;i++)
    {
        fscanf(fin,"%d %d",&x,&y);
        v[x].push_back(y);
    }
}

void parcurgere(int s)
{
    bool viz[100001];
    int u;
    for(int i=1;i<=n;i++)
    {
        viz[i]=0;
        tata[i]=0;
    }

    q.push(s);
    viz[s]=1;
    d[s]=0;
    while(!q.empty())
    {
        u=q.front();
        for(vector<int>::iterator it=v[u].begin();it!=v[u].end();it++)
        {
            if(viz[*it]==0){
            q.push(*it);
            viz[*it]=1;
            tata[*it]=u;
            d[*it]=d[u]+1;
            }
        }
        q.pop();

    }

}

void afisare()
{
    fout=fopen("bfs.out","w");
    for(int i=1;i<=n;i++)
    {

            if(d[i]==0 && i!=s)
            {
                fprintf(fout,"-1 ");
            }
            else
            {
                fprintf(fout,"%d ",d[i]);
            }

    }
}

int main()
{
    citire();
    parcurgere(s);
    afisare();
    return 0;
}