Cod sursa(job #1717716)

Utilizator stefanchistefan chiper stefanchi Data 15 iunie 2016 16:50:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <queue>
#include <vector>
#include <stdio.h>
#define N 100005
using namespace std;
vector <int> g[N];
queue <int> q;
int n,m,s,rez[N];

void citire()
{
    int x,y;
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);
    scanf("%d %d %d",&n,&m,&s);

    for(int i =1 ; i <= m ; i++)
    {
        scanf("%d %d",&x,&y);
        g[x].push_back(y);
    }
}


void bfs(int x)
{

    q.push(x);
    rez[x] = 1;
    vector <int> :: iterator it;
    while(!q.empty())
    {
        int vecin = q.front();
        q.pop();
        for(it =g[vecin].begin() ; it != g[vecin].end(); ++it)
        {
            if(rez[*it] == 0)
            {
                q.push(*it);
                rez[*it] = rez[vecin] + 1;
            }
        }
    }
}

void rezolvare()
{
    for(int i = 1 ; i <= n ; i++)
    {
        if(rez[i] == 0)
        printf("%d ", -1);
        else
            printf("%d ",rez[i] - 1);
    }
}


int main()
{
    citire();
    bfs(s);
    rezolvare();
    return 0;
}