Cod sursa(job #2367924)

Utilizator alex.sirbuSirbu Alexandru alex.sirbu Data 5 martie 2019 12:54:56
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

int n, m, s; ///nr noduri, muchii si inceput
vector <int> g[100001]; ///matrice de adiacenta

void read(){
    fin>>n>>m>>s;
    for(int i=1; i<=m; i++){
        int x, y;
        fin>>x>>y;
        g[x].push_back(y);
    }
}

int cost[100001];
queue <int> q;
void BFS(int nod){
    for(int i=1; i<=n; i++) ///initializarea costului cu 0
        cost[i]=-1;
    cost[nod]=0;
    q.push(nod);
    for(int i=1; !q.empty(); i++){
        for(int j=0; j<g[q.front()].size(); j++){
            if(cost[g[q.front()][j]]==-1){
                q.push(g[q.front()][j] );
                cost[g[q.front()][j]]=cost[q.front()]+1;
            }
        }
        q.pop();
    }

}

int main()
{
    read();
    BFS(s);
    for(int i=1; i<=n; i++)
        fout<<cost[i]<<' ';
}