The document discusses implementing a stack using a linked list as an alternative to an array. It explains that a linked list avoids size limitations of an array implementation. Elements can be inserted and removed from the start of the list in constant time, making it suitable for a stack. The four basic stack operations - push, pop, top, and isEmpty - can all be performed in constant time on this linked list implementation.

1. Class No.06 Data Structures http://ecomputernotes.com

5. Stack Operation: List int pop() { int x = head->get(); Node* p = head; head = head->getNext(); delete p; return x; } top 2 5 7 1 7 5 2 head http://ecomputernotes.com

6. Stack Operation: List void push(int x) { Node* newNode = new Node(); newNode->set(x); newNode->setNext(head); head = newNode; } top 2 5 7 9 7 5 2 head push(9) 9 newNode http://ecomputernotes.com

22. Infix to Postfix Infix Postfix A + B A B + 12 + 60 – 23 12 60 + 23 – (A + B)*(C – D ) A B + C D – * A  B * C – D + E/F A B  C*D – E F/+ http://ecomputernotes.com