Cod sursa(job #1839364)

Utilizator alex_topTop Alexandru alex_top Data 2 ianuarie 2017 20:24:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define inf 2000000000
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,i,s,x,y,d[100005];
vector <int>v[100005];
bool viz[100005];
queue <int>q;
void bfs()
{
    q.push(s);
    d[100005]=1;
    while(!q.empty())
    {
        int curr=q.front();
        q.pop();
        for(auto & it :v[curr])
        {
            if(!viz[it])
            {
                d[it]=min(d[it], d[curr] + 1);
                q.push(it);
                viz[it] = 1;
            }
        }
    }
}
int main()
{
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
    }
    for(i=1;i<=n;i++)
    {
        d[i]=inf;
    }
    d[s]=0;
    bfs();
    for(i=1;i<=n;i++)
    {
        if(d[i]!=inf) g<<d[i]<<" ";
        else g<<-1<<" ";
    }
    return 0;
}