# 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