BinarySearch 缺少所需的位置参数

Question

抱歉 - 对 Python 来说还是新手，但我的代码无法正常工作。 我真的不知道在哪里移动声明的变量并让它工作。 但是，如果我将它们放在函数之外，其他函数将被忽略并直接进入 n 的输入请求。 有任何解决这个问题的方法吗？

编辑：添加了整个代码以及我在底部遇到的错误，我不知道这是否是一个简单的缩进错误。

# menu selector
from tkinter.tix import Select


select = 0
def DisplayMenu() :
    print ("enter your choice")
    print ("1 for a Linear Search")
    print ("2 for a Binary Search")
    print ("3 for a Bubble Sort")
    print ("4 for a Selection Sort")
    print ("5 for a Insertion Sort")
def SelectRoutine() :
    global select
    DisplayMenu()
    select = int(input())
    if (select == 1) :
        print ("Call the Linear Search Routine")
        LinearSearch()
    elif (select == 2) :
        print ("Call the Binary Search Routine")
        BinarySearch()
    elif (select == 3) :
        print ("Call the Bubble Sort Routine")
        BubbleSort()
    elif (select == 4) :
        print ("Call the Selection Sort")
        SelectionSort()
    elif (select == 5):
        print ("Call the Insertion Sort")
        InsertionSort()
    else :
        print("invalid selection")
def LinearSearch() :
    elements = [10, 20, 80, 70, 60, 50]
    x = int(input("please enter the number to search: "))
    found = False
    for i in range(len(elements)) :
        if(elements[i] == x) :
            found = True
            print("%d found at %dth position" % (x, i))
            break
    if (found == False) :
            print("%d is not in list" % x)
def BinarySearch(n, sortedlist, x) :
    start = 0
    end = n - 1
    for i in range(n) :
        sortedlist.append(int(input("Enter %dth element: " % i)))
    while(start <= end) :
        mid = int((start + end) / 2)
    if (x == sortedlist[mid]) :
        return mid
    elif(x < sortedlist[mid]) :
        end = mid - 1
    else :
        start = mid + 1
        return -1
    n = int(input("Enter the size of the list: "))
    sortedlist = []
    x = int(input("Enter the number to search: "))
    position = BinarySearch(n, sortedlist, x)
    if (position != -1) :
        print("element number %d is present at position: %d" % (x,position))
    else :
        print("element number %d is not present in the list" % x)
SelectRoutine()

enter your choice
1 for a Linear Search
2 for a Binary Search
3 for a Bubble Sort
4 for a Selection Sort
5 for a Insertion Sort
2
Call the Binary Search Routine
Traceback (most recent call last):
  File "/Users/uglycode.py", line 68, in <module>
    SelectRoutine()
  File "/Users/uglycode.py", line 22, in SelectRoutine
    BinarySearch()
TypeError: BinarySearch() missing 3 required positional arguments: 'n', 'sortedlist', and 'x'

实际的

Answer 1

运行BinarySearch函数时，您应该传递n、sortedlist、位置变量。

1. 您应该在BinarySearch函数之外定义变量n、sortedlist、位置。
2. 您在while 循环下的缩进是错误的。 您应该在while函数下运行二进制搜索逻辑。
3. 如果您想在需要时运行BinarySearch函数，请将其全部作为run_binary_search()函数

如果1.和2.不修改，代码会陷入死循环。

如果你将它应用到SelectRoutine()那么你应该定义def BinarySearch()函数。

def BinarySearch():
    def _binary_serach(n, sortedlist, x):
        start = 0
        end = n - 1
        while (start <= end) :
            mid = int((start + end) / 2)
            if (x == sortedlist[mid]):
                position = mid
                break
            elif(x < sortedlist[mid]):
                end = mid - 1
            else:
                start = mid + 1
                position = -1
        if (position != -1) :
            print("element number %d is present at position: %d" % (x,position))
        else :
            print("element number %d is not present in the list" % x)
        return position

    n = int(input("Enter the size of the list: "))
    sortedlist = []
    for i in range(n):
        sortedlist.append(int(input("Enter %dth element: " % i)))
    x = int(input("Enter the number to search: "))
    position = _binary_serach(n, sortedlist, x)
    return position