Python ：我应该将 while 循环放在哪里才能使这个二进制搜索代码起作用？

Question

所以，我只是处于初学者水平，正在尝试运行这个二进制搜索代码。但是我的代码只对列表"only once"进行了划分，给出了答案。我如何让它循环直到找到中点并将索引值作为输出。

user_input = (int(input("Enter a number you want to find : ")))

lister = [i for i in range(1,100)]






def bi_search(a,user):
  low = 0
  high = len(a)
  mid = int(low + (high-low)/2)
  while True:
    if user < a[mid]:
      low = 0
      high = mid-1
      mid = int(low + (high-low)/2)
      print("Your number is in left half")
      print("Your number is",mid,"thelement in the list")
      break      
    elif user > a[mid]:
      low= mid+1
      high = len(a)
      mid = int(low + (high-low)/2)
      print("Your number is in right half")
      print("Your number is",mid,"th element in the list")
      break      

bi_search(lister,user_input)

Answer 1

您的代码几乎没有错误。您多次获得 mid 并且几乎没有其他错误。我已经编辑了您的 bi_search 并在下面提供。

代码：

def bi_search(a,user):
        low = 0
        high = len(a)
        while low <= high:   
            mid = low + (high - low) // 2
            val = a[mid]
            if user == val:
                return mid
            elif user > val:
                low = mid+1
            elif user < val:
                high = mid-1

Python ：我应该将 while 循环放在哪里才能使这个二进制搜索代码起作用？

Python : Where should I place the while loop for this Binary search code to work?

python

algorithm

binary-search

python-2.7

python-3.x