Reverse a Stack Using Recursion

Reverse the supplied stack in place using recursion and stack operations. Use scalar saved values and the implicit recursive call stack, not another data…

Reverse the supplied stack in place using recursion and stack operations. Use scalar saved values and the implicit recursive call stack, not another data container. Serialized lists are bottom to top: the final element is the top. For [1, 2, 3], the result is [3, 2, 1], with 1 now on top. Implement reverse_stack(stack) in Python or reverseStack(stack) in the other languages. Mutate the supplied stack and return no replacement.

- 0 <= stack size <= 100. Empty reversal is a no-op. - Values are signed-int32 integers; duplicates and zero are valid. - Use push, pop, top/peek, emptiness checks and recursive calls with scalar locals. - Do not use loops, indexed rearrangement, library reversal, a stack copy or another collection in the intended solution. - Return None in Python, undefined in JavaScript, and void in Java/C++. - Output grading checks the original stack's final values; it cannot prove recursion or the absence of temporary storage. References and teaching follow those restrictions. - Coding supports 100 items; complete teaching journeys support at most 6 items and display all 7 possible algorithm frames.

Example 1: input stack = [1,2,3]; output [3,2,1]. The old bottom 1 becomes the new top.

Example 2: input stack = []; output []. The empty base case needs no stack mutations.

Example 3: input stack = [4,4,-2]; output [-2,4,4]. Both occurrences of 4 remain; reversal is not sorting or deduplication.

Category: Recursion. Topic: recursion. Difficulty: Medium. Patterns: recursion, stack.