Cod sursa(job #2812726)

Utilizator elenacurecheriuElena Curecheriu elenacurecheriu Data 4 decembrie 2021 22:34:18
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.04 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

const int N = 100001;
const int inf = 0x3f3f3f;

queue <int> q;
vector <int> g[N];
int dist[N];

int n,m,s;
int x,y;

void bfs(int s)
{
    for (int i = 1; i <= n; i++)
        dist[i]=inf;
    dist[s] = 0;
    queue <int> q;
    q.push(s);
    while (!q.empty())
    {
        int nod = q.front();
        q.pop();
        int x=g[nod].size();
        for (int i = 0; i < x; i++)
        {
            if (dist[g[nod][i]] > dist[nod] + 1)
            {
                dist[g[nod][i]] = dist[nod] + 1;
                q.push(g[nod][i]);
            }
        }
    }
}
int main()
{
    fin>>n>>m>>s;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
    }
    bfs(s);
    for (int i=1; i<=n; i++)
    {
        if (dist[i]==inf)
            fout<<"-1 ";
        else
            fout<<dist[i]<<" ";
    }
    return 0;
}