Cod sursa(job #2383370)

Utilizator stan_flaviusStan Flavius Stefan stan_flavius Data 19 martie 2019 13:16:25
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
#include <vector>
#include <queue>
#define nmax 100001

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

int n,m,x;
//vector < vector <int> >v;
vector<int> v[nmax];

int dist[nmax];
int viz[nmax];

void read()
{
    fin>>n>>m>>x;
    int val1,val2,i;
    for(i=1; i<=m; i++)
       {
           fin>>val1>>val2;
           v[val1].push_back(val2);
       }
}

void bfs(int x)
{
    int i;
    queue<int>C;
    C.push(x);

    while(!C.empty())
         {
             int node=C.front();
             C.pop();

             int ct=v[node].size();
             for(i=0; i<ct; i++)
                 {
                   int val=v[node][i];
                   if(dist[val]==n) {dist[val]=dist[node]+1; C.push(val);}
                 }
         }
}

int main()
{
    read();
    for(int i=1; i<=n; i++)
         dist[i]=n;
    dist[x]=0;
    bfs(x);
    for(int i=1; i<=n; i++)
         if(dist[i]!=n) fout<<dist[i]<<" ";

              else fout<<-1<<" ";

    return 0;
}