Cod sursa(job #1650836)

Utilizator ErikHEErik Henning ErikHE Data 11 martie 2016 20:49:00
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <limits.h>
using namespace std;

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

int n, m, nd, NEVIZITAT=INT_MAX;
vector<int> G[100002];
queue<int> Q;
int cost[100002],j;

void parc_latime(int plecare)   {
int i,j;
for (i=1;i<=n;i++)
    cost[i] = NEVIZITAT;//SAU memset(Cost, -1, sizeof(Cost))
cost[plecare] = 0;
Q.push(plecare);

while ( !Q.empty() )    {
    i = Q.front();
    Q.pop();
    int j;
    //for (int & e : G[i])
    for (j=0; j<G[i].size(); j++)   {
        int e = G[i][j];
        if (cost[e] == NEVIZITAT)   {
            Q.push(e);

            cost[e] = cost[i] + 1;
        }
    }
    }
}

int main()
{
    int i, x, y;
    f>>n>>m>>nd;//nd = nod de start
    for (i=1;i<=m;i++)  {
        f>>x>>y;
        G[x].push_back(y);
    }
    parc_latime(nd);

    for (i=1;i<=n;i++)
        if (cost[i] == NEVIZITAT)
            g<<-1<<" ";
        else
            g<<cost[i]<<" ";

    return 0;
}