• Review solutions.
• Discuss any issues and common mistakes encountered.
• Clarify doubts related to the home task.

• If any of the students faced issues with basic concepts like arrays, linked lists, or queues, address those foundational concepts briefly before moving forward.
• Explain the Stack data structure to everyone:
  • A Stack is a Last-In, First-Out (LIFO) structure.
  • It works similarly to a stack of plates: the last plate added is the first one to be removed.
  • The key operations are:
    • push(item): Adds an item to the top of the stack.
    • pop(): Removes the item from the top of the stack.
    • peek(): Views the item at the top without removing it.
    • isEmpty(): Checks if the stack is empty.

• Explain the Stack data structure and its real-world analogy (like a stack of plates).
• Discuss key operations:
  • push(item): Adds an item to the top of the stack.
  • pop(): Removes an item from the top of the stack.
  • peek(): Returns the item at the top of the stack without removing it.
  • isEmpty(): Checks if the stack is empty.

• Guide students to implement a Stack class in JavaScript.
• The class should support the following methods:
  • push(item)
  • pop()
  • peek()
  • isEmpty()

Example:

class Stack {
  constructor() {
    this.items = [];
  }

  // Adds an item to the top of the stack
  push(item) {
    this.items.push(item);
  }

  // Removes the item from the top of the stack
  pop() {
    if (this.isEmpty()) {
      return 'Stack is empty';
    }
    return this.items.pop();  // Removes the last item
  }

  // Returns the item at the top without removing it
  peek() {
    if (this.isEmpty()) {
      return 'Stack is empty';
    }
    return this.items[this.items.length - 1];  // The last item in the stack
  }

  // Checks if the stack is empty
  isEmpty() {
    return this.items.length === 0;
  }
}

• Assign a task where students need to solve a problem using the Stack.
• Example problem: Implement a function to reverse a string using a Stack.

• Provide a LeetCode problem that can be solved using the Stack data structure.
• Students can work on this problem during the session or as homework.

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