li = [i for i in range(1,101)] start_index = 0 end_index = len(li)-1 num = int(input('您要找的数是:') while start_index <= end_index : mid_index = (start_index + end_index)//2 if li[mid_index] ==38 : print('您找到了') break elif li[mid_index] > 38: end_index = mid_index -1 elif li[mid_index]< 38: start_index = mid_index +1 else: print('很遗憾没有找到') #函数改写 def binarysearch(l1,num): start_index = 0 end_index = len(l1)-1 while start_index<=end_index: mid_index = (start_index+end_index)//2 if l1[mid_index] == num: return mid_index elif l1[mid_index] > num: end_index = mid_index - 1 else: start_index = mid_index+1 return -1