使用python实现二分法

Posted 2020-09-27

def f1(src_list,find_n):

    if find_n > src_list[-1]:                                #判断find_n是否大于最大值，如果大于则直接返回

        s = "%s is not finded" % (find_n)

        print(s)

        return False

    if find_n < src_list[0]:                                 #判断find_n是否小于最小值，如果小于则直接返回

        s = "%s is not finded" % (find_n)

        print(s)

        return False

    else:                                                   #只有find_n在最大值和最小值之间，才进入函数

        mid = int(len(src_list)/2)

        if len(src_list) > 1:

            if src_list[mid] > find_n:

                print("%s in left" %(find_n))

                mid_list = src_list[0:mid]

                f1(mid_list,find_n)

            elif src_list[mid] < find_n:

                print("%s in right" %(find_n))

                mid_list = src_list[mid:]

                f1(mid_list,find_n)

            else:

                print("%s is finded" %(find_n))

                return True

        if len(src_list) == 1:

            if src_list[0] == find_n:

                s = "%s is finded" % (find_n)

                print(s)

                return True

            else:

                s = "%s is not finded" % (find_n)

                print(s)

                return False

data = list(range(0,10,3))

f1(data,-1)