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StackUsingLinkedList.java
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StackUsingLinkedList.java
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class Node {
int data;
Node next;
Node(int d) {
data=d;
next=null;
}
}
class Stack {
Node top;
Stack() {
top = null;
}
boolean isEmpty() {
return (top == null);
}
void push(int x) {
Node newNode = new Node(x);
if (top == null) {
top = newNode;
} else {
newNode.next = top;
top = newNode;
}
System.out.println(x + " pushed into stack");
}
int pop() {
if (isEmpty()) {
System.out.println("Stack Underflow");
throw new java.util.EmptyStackException();
} else {
int x = top.data;
top = top.next;
return x;
}
}
int peek() {
if (isEmpty()) {
System.out.println("Stack is empty");
throw new java.util.EmptyStackException();
} else {
return top.data;
}
}
}
public class StackUsingLinkedList {
public static void main(String args[]) {
Stack stack = new Stack();
stack.push(10);
stack.push(20);
stack.push(30);
System.out.println(stack.pop() + " Popped from stack");
System.out.println("Top element is " + stack.peek());
}
}