vault backup: 2024-12-01 23:50:59

Data Structures/GPT Answers to Past Paper/Question 2.md

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+# Describe a scenario where a stack data structure would be more suitable than a  Queue
+
+A **stack data structure** is more suitable than a queue in scenarios where you need to process items in a **Last-In, First-Out (LIFO)** order
+### Scenario: **Undo Operation in Text Editors**
+
+- **Description**: In text editors, when a user types, deletes, or performs other actions, these operations are stored so they can be undone in reverse order of execution.
+- **Why a Stack?**:
+    - The most recent action (the "last-in") is the first one that should be undone (the "first-out").
+    - A stack efficiently tracks these operations, allowing actions to be added to the stack as they occur and popped off when the user undoes them.
+- **How It Works**:
+    1. User types "Hello" → each character is pushed onto the stack.
+    2. User presses "Undo" → the stack pops the last character added.
+
+### Scenario: **Call Stack in Recursion**
+
+- **Description**: When a program uses recursion, the function calls are nested, and each call must finish before the previous one can resume.
+- **Why a Stack?**:
+    - The current function (most recent call) must finish execution (be "popped" off the stack) before the previous function call can resume.
+    - The stack keeps track of the state and local variables for each function call.
+- **How It Works**:
+    1. Function `A` calls `B`, which calls `C`.
+    2. The stack stores the execution state of `A`, then `B`, then `C` (last-in).
+    3. When `C` finishes, its state is removed (first-out), resuming `B`.
+
+### Scenario: **Browser Backtracking**
+
+- **Description**: When navigating a web browser, the "Back" button relies on a stack to revisit the most recently visited page.
+- **Why a Stack?**:
+    - The most recent page (last-in) should be revisited first (first-out) when the user clicks "Back".
+- **How It Works**:
+    1. User navigates to pages: A → B → C. Each page is pushed onto the stack.
+    2. Clicking "Back" pops the stack, returning to page `B`, then `A`.
+
+### Key Contrast with a Queue:
+
+- A **queue** is more suitable when processing items in a **First-In, First-Out (FIFO)** order, such as serving customer requests or scheduling tasks.
+- A stack is better when you need **reversal** or to **process the most recent element first**, such as undo operations, recursion, or browser backtracking.
+
+Describe a scenario where a stack data structure would be more suitable than a  
+Queue