多期二叉树

def solve(____):
    import math
    q = (____ + r - d) / (____)
    call_price = ____
    for i in range(____):
        ST = S * (____) * (d ** (____))
        payoff = max(____)
        prob = math.comb(____) * (____) * ((____ - q) ** (____))
        call_price += prob * payoff
    call_price = call_price / ((____ + r) ** n)
    return {"____": n, "____": round(____), "____": round(____)}