Cod sursa(job #2961487)

Utilizator Teodor11Posea Teodor Teodor11 Data 6 ianuarie 2023 16:08:05
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.5 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

int n, m, s;
const int MAX_SIZE = 100000;
vector<int> cost, neighbors[MAX_SIZE + 1];
queue<int> nodes;

void shortest_path(int node)
{
    for (int i = 0; i <= n; ++i)
    {
        cost.push_back(-1);
    }
    cost[node] = 0;
    nodes.push(node);
    while (!nodes.empty())
    {
        /*
        cout << "Nodes: ";
        for (auto i = nodes.begin(); i != nodes.end(); ++i) {
            cout << *i << ' ';
        }
        cout << "\n\nCost: ";
        for (int i = 1; i <= n; ++i) {
            cout << '[' << i << "] " << cost[i] << ' ';
        }
        cout << "\n\n";
        */
        int act_node = nodes.front();
        int neighbors_num = neighbors[act_node].size();
        nodes.pop();
        for (int i = 0; i < neighbors_num; ++i)
        {
            int act_neighbor = neighbors[act_node][i];
            if (cost[act_neighbor] == -1)
            {
                //cout << *i << endl;
                nodes.push(act_neighbor);
                cost[act_neighbor] = cost[act_node] + 1;
            }
        }
    }
}

int main()
{
    ifstream fin("bfs.in");
    ofstream fout("bfs.out");
    fin >> n >> m >> s;
    for (int i = 0; i < m; ++i)
    {
        int x, y;
        fin >> x >> y;
        neighbors[x].push_back(y);
    }
    shortest_path(s);
    for (int i = 1; i <= n; ++i)
    {
        fout << cost[i] << ' ';
    }
    return 0;
}