Cod sursa(job #1455584)

Utilizator CollermanAndrei Amariei Collerman Data 28 iunie 2015 15:29:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ofstream fout("bfs.out");
ifstream fin("bfs.in");
const int NMAX = 100001;

int n, m, s;
int viz[NMAX];
vector<int> v[NMAX];
queue<int> q;

void citire()
{
    int x, y;

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

void bfs(int primul)
{
    int top;
    fill_n(viz, NMAX, -1);
    viz[primul] = 0;
    q.push(primul);

    while(!q.empty()) {
        top = q.front();
        q.pop();
        for(int i=0; i<v[top].size(); i++) {
            if(viz[v[top][i]] == -1) {
                viz[v[top][i]] = viz[top] + 1;
                q.push(v[top][i]);
            }
        }
    }
}

void afis()
{
    for(int i=1; i<=n; i++) {
        if(!viz[i] && i != s) fout << -1 << ' ';
        else if(viz[i]) fout << viz[i] << ' ';
        else fout << '0' << ' ';
    }
}

int main()
{
    citire();
    bfs(s);
    afis();

    fin.close();
    fout.close();
    return 0;
}