Cod sursa(job #2924536)

Utilizator vladadAndries Vlad Andrei vladad Data 4 octombrie 2022 18:04:50
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include<fstream>
#include<vector>
#include<queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n, m, s;
vector<vector<int>>v;
vector<int>viz;
vector<int>dist;
queue<int> q;
void bfs(int nod)
{
    viz[nod] = 1;
    dist[nod] = 0;
    q.push(nod);
    while(!q.empty())
    {
        int newNod = q.front();
        q.pop();
        for(auto next: v[newNod])
        {
            if(!viz[next])
            {
                viz[next] = 1;
                if(dist[next] > dist[newNod] + 1)
                    dist[next] = dist[newNod] + 1;
                q.push(next);
            }
        }
    }
}
int main()
{
    f >> n >> m >> s;
    v.resize(n + 1);
    dist.resize(n + 1);
    viz.resize(n + 1);
    for(int i = 0; i <= n; i++)
        dist[i] = (1 << 30);
    for(int i = 0; i <= n; i++)
        viz[i] = 0;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        v[x].push_back(y);
    }
    bfs(s);
    for(int i = 1; i <= n; i++)
    {
        if(dist[i] == 1 << 30)
            dist[i] = -1;
        g << dist[i] << ' ';
    }
    return 0;
}