Cod sursa(job #2379871)

Utilizator irinaS13Sandu Irina irinaS13 Data 14 martie 2019 10:49:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.91 kb
#include <fstream>
#include <queue>
#include <vector>

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

queue <int> q;
vector <int> cost;
vector <vector<int> > g;

vector <int> bfs(int S)
{
    cost[S]=0;
    q.push(S);
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for(auto vecin:g[nod])
        {
            if(cost[vecin]>cost[nod]+1)
            {
                cost[vecin]=cost[nod]+1;
                q.push(vecin);
            }
        }

    }
    return cost;
}
int main()
{
    int N,M,S;
    fin>>N>>M>>S;
    cost = vector<int> (N+1, N);
    g = vector <vector<int> > (N+1);
    for(int i=1;i<=M;i++)
    {
        int x,y;
        fin>>x>>y;
        g[x].push_back(y);
    }
    bfs(S);
    for(int i=1;i<=N;i++)
    {
        if(cost[i]==N) cost[i]=-1;
        fout<<cost[i]<<" ";
    }

    return 0;
}