Cod sursa(job #2235977)

Utilizator anisca22Ana Baltaretu anisca22 Data 27 august 2018 15:27:39
Problema BFS - Parcurgere in latime Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.48 kb
#include <bits/stdc++.h>
#define NMAX 100005
#define INF 0x3f3f3f3f

using namespace std;

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

int N, M, S;
int parc[NMAX], inq[NMAX];
vector <int> v[NMAX];
queue <int> q;
void dfs(int nod)
{
    for (vector <int> :: iterator it = v[nod].begin(); it != v[nod].end(); it++)
    {
        int nxt = *it;
        if (parc[nod] + 1 < parc[nxt])
        {
            parc[nxt] = parc[nod] + 1;
            dfs(nxt);
        }
    }
}

void bfs()
{
    parc[S] = 0;
    q.push(S);
    while (!q.empty())
    {
        int nod = q.front();
        q.pop();
        inq[nod] = 0;
        for (vector <int> :: iterator it = v[nod].begin(); it != v[nod].end(); it++)
        {
            int nxt = *it;
            if (parc[nod] + 1 < parc[nxt])
            {
                parc[nxt] = parc[nod] + 1;
                q.push(nxt);
                if (!inq[nxt])
                {
                    q.push(nxt);
                    inq[nxt] = 1;
                }
            }
        }
    }
}

void afisare()
{
    for (int i = 1; i <= N; i++)
        if (parc[i] == INF)
            fout << "-1 ";
        else fout << parc[i] << " ";
}

int main()
{
    memset(parc, INF, sizeof(parc));
    fin >> N >> M >> S;
    for (int i = 1; i <= M; i++)
    {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
    }
    parc[S] = 0;
    dfs(S);
    //bfs();
    afisare();
    return 0;
}