Cod sursa(job #2383300)

Utilizator bleo16783FMI Bleotiu Cristian bleo16783 Data 19 martie 2019 12:28:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.87 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define N 100100
#define pb push_back
using namespace std;
int i,n,d[N],x,y,S,m,k;
queue <int> q;
vector <int> a[N];
int main()
{
    ifstream fin ("bfs.in");
    fin >> n >> m >> S;
    --S;
    for (i = 0; i < m; ++i){
        fin >> x >> y;
        --x;
        --y;
        a[x].pb(y);
    }
    for (i = 0 ;i < n; ++i)
        d[i] = -1;
    d[S] = 0;
    q.push(S);
    while (!q.empty()){
        k = q.front();
        q.pop();
        int nod;
        for (int i = 0; i < a[k].size(); ++i){
            nod = a[k][i];
            if (d[nod] < 0 || d[k] + 1 < d[nod]){
                d[nod] = d[k] + 1;
                q.push(nod);
            }
        }
    }
    ofstream fout ("bfs.out");
    for (i = 0 ;i < n; ++i)
        fout << d[i] << ' ';
    return 0;
}