Python 二分查找

def two_lookup(list, element):

    low = 0
    high = len(list) - 1

    while low <= high:

        mid = (low + high) // 2

        if element == list[mid]:

            print('list[{}]={}'.format(mid,element))
            return

        elif element > list[mid]:
            low = mid + 1

        else:
            high = mid - 1

    return


list = [1, 2, 3, 4, 5, 6, 7, 8, 9]
element = 7
two_lookup(list, element)

# list[6]=7

优点 : 查找速度快, 每次都能减少一半的范围

缺点 : 只适用于有序列表

时间复杂度 : O(logn)