Cod sursa(job #3251414)

Utilizator denisdalanDenis Dalan denisdalan Data 25 octombrie 2024 22:46:36
Problema BFS - Parcurgere in latime Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.84 kb
#include <vector>
#include <queue>
#include <cstring>
#include <fstream>
using namespace std;

#define maxn 100000

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

vector<int> ad[maxn];
int cost[maxn];

void bfs(int s)
{
    memset(cost, -1, sizeof(int) * maxn);  // initialize the cost array

    queue<int> q;
    cost[s] = 0;
    q.push(s);

    while (!q.empty())
    {
        int u = q.front();
        q.pop();

        for (int v : ad[u])
        {
            if (cost[v] == -1)
            {
                cost[v] = cost[u] + 1;
                q.push(v);
            }
        }
    }
}

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

    for (int i = 0; i < m; ++i)
    {
        in >> x >> y;
        ad[x].push_back(y);
    }

    bfs(s);

    for (int i = 1; i <= n; ++i)
    {
        out << cost[i] << ' ';
    }

    return 0;
}