Cod sursa(job #1167513)

Utilizator andi23roscaRosca Andrei andi23rosca Data 5 aprilie 2014 12:38:40
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
#define maxn 100010
ifstream f("bfs.in");
ofstream g("bfs.out");
std::queue<long long> stiva;
std::vector<long long> muchie[maxn];
long long n,m,s,i,j,v[maxn],c[maxn],distanta=0,ok=0,x,y;
void citire()
{
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        muchie[x].push_back(y);
    }
}

void bfs()
{
    while(!stiva.empty())
    {
        long long nod=stiva.front();
        v[nod]=1;
        distanta=c[nod]+1;
        stiva.pop();
        for(i=0;i<muchie[nod].size();i++)
        {
            if(v[muchie[nod][i]]!=1)
            {
                stiva.push(muchie[nod][i]);
                c[muchie[nod][i]]=distanta;
            }
        }
    }
}

int main()
{
    citire();
    stiva.push(s);
    bfs();
    for(i=1;i<=n;i++)
    {
        if(c[i]==0 && i!=s) g<<-1<<" ";
        else g<<c[i]<<" ";
    }
    return 0;
}