Implementing stack using linked lists
2022-09-04 22:48:25
What's the best way to implement a stack using linked lists in Java?
EDIT: I would define best as most efficient using clean code. I have already used an array to implement a stack, but am not familiar with link lists so was wondering if anyone could help me implement something similar to below:
public class StackArray{
private Object [] objArray;
private int stackSize;
public StackArray(){
objArray = new Object[50];
stackSize = 0;
}
public StackArray(int size){
objArray = new Object[size];
stackSize = 0;
}
//public interface methods - push, pop, top, empty & clear
public void push(Object o)throws StackArrayException{
if(stackSize < objArray.length){
objArray[stackSize] = o;
stackSize ++;
}else{
throw new StackArrayException("Stack Overflow");
}
}
public Object pop()throws StackArrayException{
if(stackSize != 0){
stackSize--;
return(objArray[stackSize]);
}else{
throw new StackArrayException("Stack Underflow");
}
}
public void top() throws StackArrayException{
if(stackSize != 0){
return(objArray[stackSize-1]);
}else{
throw new StackArrayException("Stack Underflow");
}
}
public boolean empty(){
return (stackSize == 0):
}
public void clear(){
stackSize = 0;
}
}
EDIT: Here is the linked list implementation if anyone is interested..
public class StackList{
private Node listHead;
protected class Node{
protected Object datum;
protected Node next;
public Node(Object o, Node n){
datum = o;
next = n;
}
public StackList(){
listHead = null;
}
//public interface methods - push pop top empty clear
public void push(Object o){
listHead = new Node(o, listHead);
}
public Object pop() throws StackListException{
if(listHead!=null){
Object top = listHead.datum;
listHead = listHead.next;
return top;
}else{
throw new StackListException("Stack Underflow");
}
}
public Object top()throws StackListException{
if(listHead != null){
return(listHead.datum);
}else{
throw new StackListException("Stack Underflow");
}
}
public boolean empty(){
return (listHead == null);
}
public void clear(){
listHead = null;
}
}