Cod sursa(job #2783994)

Utilizator MenelausSontea Vladimir Menelaus Data 15 octombrie 2021 15:34:37
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

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

const int N=100000;

std::vector<int> v[N+1];
bool visited[N+1];
int cost[N+1];

std::queue<int> q;

void Bfs()
{
    while(!q.empty())
    {
        int curent=q.front();
        //std::cout<<curent<<" ";

        for(int i : v[curent])
        {
            if(!visited[i])
            {
                cost[i]=cost[curent]+1;
                q.push(i);
            }
        }

        visited[curent]=1;
        q.pop();
    }
}

int main()
{
    int n, m, s, x, y;

    in>>n>>m>>s;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        if(x!=y) v[x].push_back(y);
    }

    q.push(s);
    Bfs();

    for(int i=1; i<=n; i++)
    {
        if(i==s) out<<0<<" ";
        else
        {
            if(cost[i]==0)
            {
                out<<-1<<" ";
            }
            else
            {
                out<<cost[i]<<" ";
            }
        }
    }
}