int BFS(G: (V, E), source: int, destination: int):
    d = int[|V|]
    fill(d, ∞)
    d[source] = 0
    Q = ∅
    Q.push(source)
    while Q ≠∅
        u = Q.pop()
        for vu in E
            if d[v] == ∞
                d[v] = d[u] + 1
                Q.push(v)
    return d[destination]