Cod sursa(job #2475359)

Utilizator ViAlexVisan Alexandru ViAlex Data 16 octombrie 2019 20:07:56
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include<bits/stdc++.h>

using namespace std;

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


struct nod
{
    int index;
    int cost;

};

vector<int> adiacenta[100001];
bool parcurs[100001];
int results[100001];
int n,m,s;

void read()
{
    in>>n>>m>>s;
    int a,b;
    for(int i=0; i<m; i++)
    {
        in>>a>>b;
        adiacenta[a].push_back(b);
    }

}

void bfs()
{
    nod inceput{s,0};
    deque<nod> l;
    parcurs[inceput.index]=true;
    l.push_back(inceput);

    while(l.size())
    {
        nod a=l.front();
        for(int i=0; i<adiacenta[a.index].size(); i++)
        {
            if(!parcurs[adiacenta[a.index][i]])
            {
                parcurs[adiacenta[a.index][i]]=true;
                nod b{adiacenta[a.index][i],a.cost+1};
                results[b.index]=b.cost;
                l.push_back(b);
            }

        }
        l.pop_front();
    }

}




int main()
{
    read();
    bfs();
    for(int i=1; i<=n; i++)
    {
        if(results[i] || i==s)
            out<<results[i]<<" ";
        else
        {
            out<<-1<<" ";
        }

    }

}