Stack implementation using Linked List

Stack implementation using Linked List

Stack using Linked List  

We have seen Stack implementation using array in our earlier tutorials. Now lets see same stack implementation using Linked List and how to push() and pop() values in Stack. Below is the simple example to push() integers into Stack internally having Linked List nodes with total stack size of 10.

class NODE {
 
 NODE link;
 int data;
 
 public NODE() {
 }
 
 public NODE(int data) {
  this.data = data;
 } 
}

public class StackUsingLinkedList {

 NODE root;
 int stackSize = 0;
 int stackLimit = 10;
 
 public static void main(String[] args) {
  
  StackUsingLinkedList obj = new StackUsingLinkedList();
  
  for(int i =0;i<11;i++){
   obj.push(i+10);
  }
  
  for(int i =0;i<11;i++){
   System.out.println(obj.pop());
  }
 }
 
 private int pop(){
  if(stackSize == 0){
   System.out.println("Stack empty ....");
   return -1;   
  }
  NODE tmp = root;
  root = root.link;
  stackSize--;
  return tmp.data;
  
 }
 
 private void push(int val){
  if(stackLimit == stackSize) {
   System.out.println("Stack Full ....");
   return;
  }
  if(root == null){
   root = new NODE(val);
   root.link = null;   
  }else{
   NODE tmp = new NODE(val);
   tmp.link = root;
   root = tmp;
  }
  System.out.println("PUSH ::: "+stackSize + " :: "+val);
  stackSize++;
 }
}

OUTPUT:

PUSH ::: 0 :: 10
PUSH ::: 1 :: 11
PUSH ::: 2 :: 12
PUSH ::: 3 :: 13
PUSH ::: 4 :: 14
PUSH ::: 5 :: 15
PUSH ::: 6 :: 16
PUSH ::: 7 :: 17
PUSH ::: 8 :: 18
PUSH ::: 9 :: 19
Stack Full ....
19
18
17
16
15
14
13
12
11
10
Stack empty ....
-1