Cod sursa(job #2727972)

Utilizator denmirceaBrasoveanu Mircea denmircea Data 22 martie 2021 17:49:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <vector>
#include <deque>
#include <fstream>
#define dim 100005
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector<int> L[dim];
int fr[dim];
int d[dim];
int n,m,start,x,y;
/// avem un vector de vectori goi
/// L[0],L[1]...L[n] reprezinta vectori care retin vecinii lui 0,1,... n
void bfs(int nod){
    fr[nod]=1;
    d[nod]=0;
    deque<int> q;
    q.push_back(nod);
    while(!q.empty()){
        int nodcurent=q.front(); /// nodul aflat in capul liste
        q.pop_front();
        /// accesam toti vecii nodului curent aflati in vectorul L[nodcurent]
        for(int i=0;i<L[nodcurent].size();i++){
            int vecin=L[nodcurent][i]; /// acesta este unul dintre vecinii nodului curent
            if(fr[vecin]==0){
                fr[vecin]=1;
                d[vecin]=d[nodcurent]+1;
                q.push_back(vecin);
            }
        }
    }
}
int main()
{
    fin>>n>>m>>start;
    for(int i=1;i<=m;i++){
        fin>>x>>y;
        L[x].push_back(y);
    }
    bfs(start);
    for(int i=1;i<=n;i++){
        if(fr[i]==0){
            fout<<-1<<" ";
        }
        else fout<<d[i]<<" ";
    }
    return 0;
}