Question

Suppose the interface and the class of stack already implemented, Write application program to ( java)

1- insert 100 numbers to the stack                        

2- Print the even numbers

3- Print the summation of the odd numbers

Answer 1

import java.util.Collections;
import java.util.Stack;

public class Main
{
    //method to print even numbers of the stack 
    public static void printEven(Stack<Integer> s1){
        
        //initialize ans array
        int[] ans = new int[50];
        int i = 0;
        
        //loop runs untill all ements of the stack are popped out
        while(s1.size() > 0){
            int n = s1.pop();
            //check is popped element is even or odd
            //modulo operator returns the remainder of integer division
            //if number is even then it is divisible by 2 so remainder is 0
            if( n % 2 == 0)
            {
                //add number to the stack
                ans[i] = n;
                i++;
            }
            
        }
        
        //prints all the even numbers
        System.out.print("Even numbers: ");
        for(int j = 0 ; j < i ; j++){
            System.out.print(ans[j] + " ");
        }
       
    }
    
    //method to print the sum of odd numbers of the stack 
    public static void printOddSum(Stack<Integer> s2){
        
        int sum = 0;
        while(s2.size() > 0){
            int n = s2.pop();
            //if number is even then add then prints the sum of all odd numbers
            if( n % 2 != 0)
            {
               sum = sum + n;
            }
            
        }
        
        //now the sum of all even numbers are stored in sum 
        System.out.println("Sum of Odd numbers:  " + sum);
       
    }   
    
        public static void main(String[] args) {
        
            //initialize Stack s1 and s2
            Stack<Integer> s1 = new Stack<>();
            Stack<Integer> s2 = new Stack<>();

        //push 100 elements in stack s1 and s2
        for(int i = 0 ; i< 100 ; i++){
            s1.push(i);
            s2.push(i);
        }

        //prints the stack content
        System.out.println("Stack" + s1);
        
        //call printOddSum
        printOddSum(s1);
        
        // call printEven method
        printEven(s2);        
        
    }
    
}

OUTPUT: