Cod sursa(job #2784015)

Utilizator MenelausSontea Vladimir Menelaus Data 15 octombrie 2021 16:05:50
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 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];

int cost[N+1];
bool visited[N+1];

std::queue<int> q;

void Bfs()
{
    while(!q.empty())
    {
        int t=q.front();
        q.pop();

        for(int i : v[t])
        {
            if(visited[i]==0)
            {
                cost[i]=cost[t]+1;
                q.push(i);
                visited[i]=1;
            }
        }
    }
}

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

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

    q.push(s);
    visited[s]=1;
    Bfs();

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

    return 0;
}