Cod sursa(job #2547207)

Utilizator VladMxPMihaila Vlad VladMxP Data 15 februarie 2020 10:02:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.87 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector <int> v[1000001];
queue <int> q;
int a[100001];
int n,m,s,x,y;
bool viz[100001];
void bfs()
{
    q.push(s);
    for(int i=1;i<=n;i++)a[i]=-1;
    a[s]=0;
    viz[s]=1;
    while(!q.empty())
    {
        int nod=q.front();
        for(int j=0;j<v[nod].size();j++)
        {
            int vecin=v[nod][j];
            if(viz[vecin]==0)
            {
                viz[vecin]=1;
                a[vecin]=a[nod]+1;
                q.push(vecin);
            }
        }
        q.pop();
    }
}
int main()
{
    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    bfs();
    for(int i=1;i<=n;i++)
    {
        fout<<a[i]<<" ";
    }
}