Cod sursa(job #3185969)

Utilizator ArseniuVictorStefanArseniu Victor Stefan ArseniuVictorStefan Data 20 decembrie 2023 22:13:07
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <stdio.h>
#include <vector>

#define NMAX (100'000)

int n, m, s;
std::vector<int> g[NMAX];

void add_edge(int u, int v)
{
    g[u].push_back(v);
}

void bfs(int s, int* distances)
{
    static int queue[NMAX];

    for(int i = 0; i < n; i++)
        distances[i] = -1;

    int top = 0;
    queue[top++] = s;
    distances[s] = 0;

    for(int front = 0; front < top; front++)
    {
        int u = queue[front];
        for(int i = 0; i < g[u].size(); i++)
        {
            int v = g[u][i];
            if(distances[v] == -1)
            {
                queue[top++] = v;
                distances[v] = distances[u] + 1;
            }
        }
    }
}

int distances[NMAX];

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);

    scanf("%d %d %d", &n, &m, &s);
    s--;

    for(int i = 0; i < m; i++)
    {
        int u, v;
        scanf("%d %d", &u, &v);
        u--; v--;

        add_edge(u, v);
    }

    bfs(s, distances);

    for(int i = 0; i < n; i++)
        printf("%d ", distances[i]);
    printf("\n");
    return 0;
}