Cod sursa(job #1501229)

Utilizator refugiatBoni Daniel Stefan refugiat Data 13 octombrie 2015 07:46:19
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.16 kb
#include<iostream>
#include<fstream>
#include<list>
#include<queue>
#include<bitset>
using namespace std;
const int PCT=100000;
list<int>gr[PCT];
queue<int> q;
queue<int> l;
int b[PCT];
void bfs(int s)
{
    list<int>::iterator i;
    q.push(s);
    l.push(0);
    int lung;
    b[s]=-1;
    while(q.size())
    {
        s=q.front();
        q.pop();
        lung=l.front();
        l.pop();
        for(i=gr[s].begin();i!=gr[s].end();++i)
        {
            if(b[*i]==0)
            {
                q.push(*i);
                l.push(lung+1);
                b[*i]=lung+1;
            }
        }
    }
}
int main()
{
    ifstream si;
    si.open("bfs.in");
    ofstream so;
    so.open("bfs.out");
    int n,m,s;
    si>>n>>m>>s;
    --s;
    int i,a,c;
    for(i=0;i<m;++i)
    {
        si>>a>>c;
        gr[a-1].push_back(c-1);
    }
    bfs(s);
    for(i=0;i<n;++i)
    {
        if(b[i]==0)
        {
            so<<-1<<' ';
        }
        else
        {
            if(b[i]==-1)
                so<<0<<' ';
            else
                so<<b[i]<<' ';
        }
    }
    so<<'\n';
    return 0;
}