Cod sursa(job #2544480)

Utilizator MarcGrecMarc Grec MarcGrec Data 12 februarie 2020 09:40:18
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.93 kb
#define MAX_N 100000
#define INF 0x3f3f3f3f

#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

int n, m, s, D[MAX_N + 1];
vector<int> G[MAX_N + 1];

int main()
{
    fin >> n >> m >> s;

    for (int i = 1; i <= n; ++i)
    {
        D[i] = INF;
    }

    for (int i = 0, x, y; i < m; ++i)
    {
        fin >> x >> y;
        G[x].push_back(y);
    }

    queue<int> Q;
    Q.push(s);
    D[s] = 0;

    while (!Q.empty())
    {
        int T = Q.front();
        Q.pop();

        for (int vecin : G[T])
        {
            if (D[vecin] > (D[T] + 1))
            {
                D[vecin] = D[T] + 1;
                Q.push(vecin);
            }
        }
    }

    for (int i = 1; i <= n; ++i)
    {
        fout << ((D[i] == INF) ? -1 : D[i]) << ' ';
    }

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