Question

Write a program that initializes an array with ten random integers and then prints out the following:

• Every element at an even index;
• Every even element
• All elements in reverse order;
• Only the first and last elements;
• The minimum and maximum element
• The sum of all elements
• The alternating sum of all elements, where the alternating sum contains all elements at even index added, and the elements at odd index subtracted.

Please write comments above the piece of code that do each bullet point. Or write pseudocode/algorithm for the program below:

package element;

import java.util.Random;

public class element {

public static void main(String a[])

{

int ar[]=new int[10];

int i,sum=0,sumeven=0,sumodd=0,min,max;

for(i=0;i<10;i++)

{

Random r = new Random();

ar[i] = r.nextInt(1000);

}

System.out.println("Elements are: ");

for(i=0;i<10;i++)

{

System.out.println("At index "+i+": "+ar[i]);

}

System.out.println("Elements at even index are: ");

for(i=0;i<10;i+=2)

{

System.out.println("At index "+i+": "+ar[i]);

}

System.out.println("Elements in reverse order: ");

for(i=9;i>=0;i--)

{

System.out.println("At index "+i+": "+ar[i]);

}

System.out.println("First element: "+ar[0]+"\nlast element: "+ar[9]);

min=ar[0];

max=ar[0];

sum+=ar[0];

for(i=1;i<10;i++)

{

sum+=ar[i];

if(ar[i]>max)

max=ar[i];

if(ar[i]

min=ar[i];

}

System.out.println("Maximum element:"+max+"\nMinimum element: "+min);

System.out.println("Sum of all element = "+sum);

for(i=0;i<10;i++)

{

if(i%2==0)

{

sumeven+=ar[i];

}

else

sumodd+=ar[i];

}

System.out.println("Alternating sum is: "+(sumeven-sumodd));

}

}

Answer 1

import java.util.Random;

public class element {

public static void main(String a[])

{

int ar[]=new int[10]; // declare an array

int i,sum=0,sumeven=0,sumodd=0,min,max; // declaration of required variables

for(i=0;i<10;i++)

{

Random r = new Random(); //create random object

ar[i] = r.nextInt(1000); // creating array of 10 random values

}

System.out.println("Elements are: ");

for(i=0;i<10;i++)

{

System.out.println("At index "+i+": "+ar[i]); // print all elements

}

System.out.println("Elements at even index are: ");

for(i=0;i<10;i+=2)

{

System.out.println("At index "+i+": "+ar[i]); //print even elements

}

System.out.println("Elements in reverse order: ");

for(i=9;i>=0;i--) // reverse loop for reverse printing

{

System.out.println("At index "+i+": "+ar[i]); //print elements in reverse order

}

System.out.println("First element: "+ar[0]+"\nlast element: "+ar[9]);

min=ar[0];

max=ar[0];

sum+=ar[0];

for(i=1;i<10;i++)

{

sum+=ar[i]; // adding each element

if(ar[i]>max)

max=ar[i]; // storing maximum value and updating with iteration

if(ar[i]<min) // storing minimum value and updating with iteration

min=ar[i];

}

System.out.println("Maximum element:"+max+"\nMinimum element: "+min);

System.out.println("Sum of all element = "+sum);

for(i=0;i<10;i++)

{

if(i%2==0)

{

sumeven+=ar[i]; // adding even indexed numbers

}

else

sumodd+=ar[i]; // adding odd indexed numbers

}

System.out.println("Alternating sum is: "+(sumeven-sumodd)); // printing difference

}

}

COMMENTS HAVE BEEN ADDED.

ALGORITHM:

STEP 1: Declare array ar and define all required variables i=0 , sum=0,sumeven=0,sumodd=0,min,max.

STEP 2: define a random object .

STEP 3: set ar[i]= r.nextInt(1000) a random number until 1000 and increment i.

[Repeat Step 3 whilei<10]

STEP 4: Print all elements.

STEP 5: set i=0.

Step 6:print ar[i] and increment i by 2.

[repeat step 5 while i<10]

Step 7: set i=9.

Step 8: print ar[i] and decrement i by 1.

[Repeat step 8 while i>=0]

step 9: print 1st element ar[0] and last element ar[9].

Step 10: set min,max,sum as ar[0] and i=1;

Step 11: add ar[i] to sum.

Step 12: if ar[i]>max , set max as ar[i].

Step 13: if ar[i]<min, set min as ar[i].

Step 14: increment i by 1.

[Repeat steps 11 to 14 while i<10]

step 15: set i=0.

step 16: if i is even, add ar[i] to sumeven.

step 17: if i is odd, add ar[i] to sumodd.

step 18: increment i by 1

[Repeat steps 15 to 18 while i<10]

step 19: subtract sumeven and sumodd and print the difference.

[END]