代码工作正常，但是我无法解决python中的所有测试用例

Question

Given a stack of integers, write a python program that updates the input stack such that all occurrences of the smallest values are at the bottom of the stack, while the order of the other elements remains the same.

For example:

Input stack (top-bottom) :   5 66  5  8  7
Output:  66  8  7  5  5

def change_smallest_value(number_stack):
    #write your logic here
    size = number_stack.get_max_size()
    li = []
    for i in range(size):
        a = number_stack.pop()
        if (a != None):
            li.append(a)
    li.sort()
    for i in li:
        number_stack.push(i)
    return number_stack

5 out of 8 test cases passed.

Answer 1

You do not show us the code for your stack, which makes it hard for us to test. But here is an algorithm in pseudocode--I'll let you fill in the code.

Create a new, empty stack
Set the minimum-value-so-far to something ridiculously large
while the old stack is not empty:
    Pop one value off the old stack
    if that value is smaller than the minimum-value-so-far:
        Set the minimum-value-so-far to the current value
        Set the frequency of that minimum to one
    else if that value equals the minimum-value-so-far:
        Increase the frequency of that minimum by one
    Push that value onto the new stack
Push the minimum value onto the old stack, the frequency number of times
while the new stack is not empty:
    Pop one value off the new stack
    if that value does not equal the minimum value:
        Push that value onto the old stack
Return the old (modified) stack

This uses an extra stack, but at no time does any item exist in both stacks simultaneously, so the memory usage of this code is O(1). The execution time is O(n) where n is the size of the stack--each item is seen twice. Moving items between two stacks twice inverts the order the first time and restores the order the second time--except for the special value (the minimum) that is handled differently.

Answer 2

li.sort() will breaks the order of your stack. remove the line