Cod sursa(job #799647)

Utilizator CrescentselectJicol Crescent Crescentselect Data 19 octombrie 2012 17:37:17
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.95 kb
#include <iostream>
#include<fstream>
#include<vector>
#include<queue>
using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

const int n = 100001;

vector <int> v[n];
queue <int> q ;

int i,j,x,y,dist[n],M,N,S;

void citire(){

    f>>N>>M>>S;
    for (i=0;i<=M ;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        //v[i].push_back(x);
    }
    for( i=1;i<=N; i++)
    {
        dist[i]=-1;
    }
}

void bfs()
{
    int x, y;
    q.push(S);
    dist [S]=0;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(size_t i=0;i<v[x].size();i++)
        {
            y=v[x][i];
            if(dist[y]==-1)
            {
                q.push(y);
                dist[y]=1+dist[x];
            }
        }
    }
}
void tipar ()
{
    for( int i=1;i<=N;i++)
    {
        g<<dist[i]<<" ";
    }
}

int main()
{
    citire();
    bfs();
    tipar();
    return 0;
}