Cod sursa(job #1503257)

Utilizator ilinoiuflaviusIlinoiu Flavius ilinoiuflavius Data 15 octombrie 2015 19:49:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <iostream>
#include <fstream>
#include <queue>
#define nmax 100001
using namespace std;

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

int n,m,s,viz[nmax];

struct nod
{
    int nr;
    nod *p;
}v[nmax];
queue <int> Q;
void add(int a,int b)
{
    nod*q = new nod;
    q->p = v[a].p;
    q->nr = b;
    v[a].p = q;
}
void read()
{
    f>>n>>m>>s;
    int a,b;
    for(int i=1;i<=m;i++)
    {
        f>>a>>b;
        add(a,b);
    }
}
void BFS(int a)
{
    viz[a]=0;
    Q.push(a);
    while(!Q.empty())
    {
        for(nod *q = v[Q.front()].p; q!=NULL; q=q->p)
        {
            if(viz[q->nr]==-1)
            {
                viz[q->nr]=viz[Q.front()]+1;
                Q.push(q->nr);
            }
        }
        Q.pop();
    }
}
void solve()
{
    BFS(s);
}
void write()
{
    for(int i=1;i<=n;i++)g<<viz[i]<<" ";
}
int main()
{
    read();
    for(int i=1;i<=n;i++)viz[i]=-1;
    solve();
    write();
    return 0;
}