Cod sursa(job #2751111)

Utilizator RTG123Razvan Diaconescu RTG123 Data 14 mai 2021 11:38:17
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.04 kb
#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n,m,k,x,y,vdr[100001],viz[100001];
vector <vector <int>> v(100001);
void exec (int start)
{
    viz[start]=1;
    queue <int> q;
    q.push(start);
    while (!q.empty())
    {
        int a=q.front();
        for (int j=0; j<v[a].size(); j++)
        {
            if (viz[v[a][j]]==0 || vdr[v[a][j]]>vdr[a]+1)
            {
                viz[v[a][j]]=1;
                vdr[v[a][j]]    =vdr[a]+1;
                q.push(v[a][j]);
            }
        }
        q.pop();
    }
}
int main()
{
    f>>n>>m>>k;
    for (int i=1; i<=m; i++)
    {
        f>>x>>y;
        v[x].push_back(y);
      //  v[y].push_back(x);
    }
    exec(k);
    for (int i=1; i<=n; i++)
    {
        if (i!=k)
        {
            if (vdr[i]>0)
                g<<vdr[i]<<' ';
            else g<<-1<<' ';
        }
        else g<<0<<' ';
    }
    return 0;
}