Cod sursa(job #3042034)

Utilizator BetJohn000Ioan Benescu BetJohn000 Data 3 aprilie 2023 18:58:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>

using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");
bool vizitat[1000000];
queue <int> coada;
vector <int> graf[1000000];
int noduri,muchii,start;
vector <int> cost;
void citire()
{
    f>>noduri>>muchii>>start;
    cost.resize(noduri+1);
    for(int i=0;i<muchii;i++)
    {
        int x,y;
        f>>x>>y;
        graf[x].push_back(y);
    }
    for(int i=1;i<=noduri;i++)
        cost[i] = -1;
    cost[start] = 0;
}
/*
5 7 2
1 2
2 1
2 2
3 2
2 5
5 3
4 5
graf:
    1: 2
    2: 1 2 5
    3: 2
    4: 5
    5: 3
*/
void BFS(int start)
{
    coada.push(start);
    vizitat[start] = true;
    while(!coada.empty())
    {
        int nodCurent = coada.front();
        coada.pop();
        for(auto vecin:graf[nodCurent])
        {
            if(vizitat[vecin] == false)
                {
                    vizitat[vecin] = true;
                    coada.push(vecin);
                    cost[vecin] = cost[nodCurent] + 1;
                }
        }
    }
}
int main()
{
    citire();
    BFS(start);
    for(int i=1;i<=noduri;i++)
        g<<cost[i]<<" ";
    return 0;
}