Cod sursa(job #1923072)

Utilizator alex_topTop Alexandru alex_top Data 10 martie 2017 20:34:59
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <iostream>
#include <queue>
#include <vector>
#define inf 2000000000
#include <fstream>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,s,x,y,i,d[100005];
queue <int> q;
vector <int> v[100005];
void BFS(int node)
{
    for(i=1;i<=n;i++)
        d[i]=inf;
    d[node]=0;
    q.push(node);
    while(!q.empty())
    {
        int curr=q.front();
        q.pop();
        for(auto & it : v[curr])
        {
            if(d[it]>d[curr]+1)
            {
                d[it]=d[curr]+1;
                q.push(it);
            }
        }
    }
}
int main()
{
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
    }
    BFS(s);
    for(i=1;i<=n;i++)
    {
        if(d[i]!=inf) g<<d[i]<<" ";
        else g<<-1<<" ";
    }
    return 0;
}