Cod sursa(job #891265)

Utilizator GManiakGhenea Catalin GManiak Data 25 februarie 2013 15:08:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream h("bfs.out");
const int nod=1000001;
vector<int> a[nod];
queue <int> q;
int d[nod],n,s;
void citire()
{
    int x,y,m,i;
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[x].push_back(x);
    }
}
void bfs(int x0)
{
    int x,y;
    for(int i=1;i<=n;i++)
        d[i]=-1;
    q.push(x0);
    d[x0]=0;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(size_t i=0;i<a[x].size();i++)
        {
            y=a[x][i];
            if(d[y]==-1)
            {
                q.push(y);
                d[y]=1+d[x];
            }
        }
    }
}
int main()
{
    citire();
    bfs(s);
    for(int i=1;i<=n;i++)
            h<<d[i]<<' ';

}