Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Implement a stack from a LinkedList in Java
A stack can be implemented using a LinkedList by managing the LinkedList as a stack. This is done by using a class Stack which contains some of the Stack methods such as push(), top(), pop() etc.
A program that demonstrates this is given as follows −
Example
import java.util.LinkedList;
class Stack {
private LinkedList l = new LinkedList();
public void push(Object obj) {
l.addFirst(obj);
}
public Object top() {
return l.getFirst();
}
public Object pop() {
return l.removeFirst();
}
}
public class Demo {
public static void main(String[] args) {
Stack s = new Stack();
s.push(5);
s.push(1);
s.push(3);
s.push(9);
s.push(7);
System.out.println("The top element of the stack is: " + s.top());
System.out.println("The stack element that is popped is: " + s.pop());
System.out.println("The stack element that is popped is: " + s.pop());
System.out.println("The top element of the stack is: " + s.top());
}
}Output
The top element of the stack is: 7 The stack element that is popped is: 7 The stack element that is popped is: 9 The top element of the stack is: 3
Now let us understand the above program.
A class Stack is created which contains some of the Stack methods such as push(), top(), pop() etc. A code snippet which demonstrates this is as follows −
class Stack {
private LinkedList l = new LinkedList();
public void push(Object obj) {
l.addFirst(obj);
}
public Object top() {
return l.getFirst();
}
public Object pop() {
return l.removeFirst();
}
}In the method main(), an object s is created of the class Stack. Then this is used to push elements into the stack, display the top element and pop elements from the stack. A code snippet which demonstrates this is as follows −
public static void main(String[] args) {
Stack s = new Stack();
s.push(5);
s.push(1);
s.push(3);
s.push(9);
s.push(7);
System.out.println("The top element of the stack is: " + s.top());
System.out.println("The stack element that is popped is: " + s.pop());
System.out.println("The stack element that is popped is: " + s.pop());
System.out.println("The top element of the stack is: " + s.top());
}
Updated on: 30-Jul-2019
2K+ Views
Advertisements