Cod sursa(job #2253486)

Utilizator andrei.gramescuAndrei Gramescu andrei.gramescu Data 4 octombrie 2018 08:46:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 1000005
using namespace std;
ifstream fin ("bfs.in");
ofstream fout ("bfs.out");

vector<int> a[NMAX];
int n, m, s, d[NMAX];

void BFS(int start) {
    queue<int> q;
    q.push(start);
    d[start] = 0;

    while(!q.empty()) {
        start = q.front();
        q.pop();
        for(int i=0; i<(int)a[start].size(); i++) {
            int x = a[start][i];
            if(d[x] == -1) {
                d[x] = d[start] + 1;
                q.push(x);
            }
        }
    }
}

int main()
{
    int x, y;

    fin >> n >> m >> s;

    for(int i=0; i<=n; i++) {
        d[i] = -1;
    }

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

    BFS(s);

    for(int i=1; i<=n; i++) {
        fout << d[i] << " ";
    }

    return 0;
}