43.Python：二分法

# 算法：高效解决问题的办法
# 算法之二分法

# 需求：有一个按照从小到大顺序排列的数字列表
#      需要从该数字列表中找到想要的那个数字

nums = [-3, 1, 4, 7, 10, 13, 21, 43, 77, 89, 100]


def b_search(find_num, w_list):
    print(w_list)
    if len(w_list) == 0:
        print('num not in list')
        return
    w_len = len(w_list) // 2
    mid_val = w_list[w_len]

    if find_num > mid_val:
        w_list = w_list[w_len + 1:]
        b_search(find_num, w_list)
    elif find_num < mid_val:
        w_list = w_list[: w_len]
        b_search(find_num, w_list)
    else:
        print('find', find_num)


b_search(89, nums)