Cod sursa(job #907560)

Utilizator Mihai20Mihai20 Mihai20 Data 8 martie 2013 01:21:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.88 kb
#include <fstream>
#include <vector>
#include <queue>
#include<iostream>

using namespace std;
#define NMAX 1000001
ifstream f("bfs.in");
ofstream h("bfs.out");
	


vector<int> Lista[NMAX];
queue <int> q;
int Cost[NMAX],n,s;
void citire()
{
    int x,y,m,i;
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        Lista[x].push_back(y);
    }
}
void bfs(int k)
{
    int x,y;
    for(int i=1;i<=n;i++)
    Cost[i]=-1;
    q.push(k);
    Cost[k]=0;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(int i=0;i<Lista[x].size();i++)
        {
            y=Lista[x][i];
            if(Cost[y]==-1)
            {
                q.push(y);
                Cost[y]=1+Cost[x];
            }
        }
    }
}
int main()
{
    citire();
    bfs(s);
    for(int i=1;i<=n;i++)
            h<<Cost[i]<<' ';
 
}