题解 | 小欧的选数乘积

def quick_sorted(arr):
    if len(arr) <= 1:
        return arr
    piovt = arr[len(arr)//2]
    left = [x for x in arr if x < piovt]
    middle = [x for x in arr if x == piovt]
    right = [x for x in arr if x > piovt]
    return quick_sorted(left) + middle + quick_sorted(right)
list1 = list(map(int, input().split(' ')))
x, y=list1[0], list1[1]
if x >= y:
    print(0)
else:
    n=int(input())
    list2 = list(map(int, input().split(' ')))
    list2_sorted = list(set(quick_sorted(list2)))[::-1] # 最大值放前，且去重
    res=x
    for i, ele in enumerate(list2_sorted):
        res *= ele
        if res >= y :
            print(i+1)
            break
    else:
        print(-1)