Cod sursa(job #3155958)

Utilizator rarestudurTudur Rares rarestudur Data 10 octombrie 2023 12:36:30
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

const int NMAX = 1e5;

int d[NMAX+1];
bool vis[NMAX+1];

queue<int > q;

vector <int> G[NMAX+1];

//bool a[NMAX+1][NMAX+1];

void BFS(int x)
{
    q.push(x);
    d[x] = 0;
    vis[x] = true;
    while(!q.empty())
    {
        int y = q.front();
        q.pop();
        for(auto i : G[y])
        {
            if(!vis[i])
            {
                q.push(i);
                vis[i] = true;
                d[i] = d[y] + 1;
            }
        }
    }
}

int main(int argc, const char * argv[])
{
    int n,m,s;
    in >> n >> m >> s;
//    for(int i = 0; i < n; i++) //citire in matrice de aficienta
//    {
//        int x,y;
//        in >> x >> y;
//        a[x][y] = a[y][x] = true;
//    }
    for(int i = 0; i < m; i++) //citire in liste de adiacenta
    {
        int x,y;
        in >> x >> y;
        G[x].push_back(y);
    }
    BFS(s);
    for(int i = 1 ; i <= n; i++)
    {
        if(d[i] == 0 && i != s)
        {
            d[i] = -1;
        }
        out << d[i] << " ";
    }
//    for(int i = 0; i < n; i++)
//    {
//        for(auto x: G[i])
//        {
//            cout << x << " ";
//        }
//    }
//    for(int i = 0; i < n; i++)
//    {
//        for(int j = 0; j < n; j++)
//        {
//            cout << a[i][j] << " ";
//        }
//        cout << "\n";
//    }
    return 0;
}