Question

(JAVA)Define a method getFrequency(anEntry) for the Linked List implementation of stack ADT. The method returns the number of occurrences of anEntry in the stack.

Answer 1

import java.util.LinkedList;

class MyStack{
    LinkedList<Integer> stack;
  
    MyStack(){
        stack = new LinkedList();
    }
  
    public void push(Integer e){
        stack.push(e);
    }
  
    public Integer pop(){
        return stack.pop();
    }
  
    public Integer peek(){
        return stack.peek();
    }
  
    public int frequency(int element){
        int count = 0;
        for(Integer x : stack){
            if(x==element){
                count++;
            }
        }
        return count;
    }
    @Override
    public String toString(){
        return stack.toString();
    }
}
class Main {

    public static void main(String[] args) {

        MyStack stack = new MyStack();
        stack.push(2);
        stack.push(2);
        stack.push(3);
        stack.push(2);
        stack.push(5);
        System.out.println("Stack is "+stack);
        System.out.println(stack.frequency(2));
    }
}

OUTPUT :