Expt 1 - Part 1, Part 2 & Part 3

Explanation

This Java code is designed to calculate and display the first 'N' natural numbers, along with their cumulative sum. It first prompts the user to enter a positive integer 'N', which represents how many natural numbers they want to see. After receiving this input, the program uses a do-while loop to iterate from 1 up to 'N'. In each iteration, it prints the current natural number and adds it to a running total (sum). Finally, once the loop completes, it prints the total sum of all the displayed natural numbers.

The logic works as follows:

1. Get Input: The program uses the Scanner class to read an integer value from the user, storing it in the n variable. This n determines how many natural numbers will be processed.
2. Initialize Variables: Two integer variables, i and sum, are initialized. i starts at 1 because natural numbers begin from 1. sum starts at 0 to ensure an accurate accumulation.
3. Loop and Calculate: A do-while loop is used.
   • The do block executes at least once. Inside this block, the current value of i (a natural number) is printed to the console.
   • Then, i is added to sum (sum += i;).
   • Finally, i is incremented (i++;) to move to the next natural number.
   • The while condition (i <= n) is checked after each execution of the do block. The loop continues as long as i is less than or equal to n. Once i becomes greater than n, the loop terminates.
4. Display Sum: After the loop finishes, the program prints the final calculated sum.
5. Close Scanner: The Scanner object is closed to release system resources.

Algorithm

1. Start the program.
2. Create a Scanner object to read user input.
3. Prompt the user to enter the number of terms (N).
4. Read the integer value for N from the user.
5. Initialize an integer variable i to 1 (for the first natural number).
6. Initialize an integer variable sum to 0.
7. Print a header indicating the display of natural numbers.
8. Begin Do-While Loop: a. Print the current value of i. b. Add the current value of i to sum. c. Increment i by 1. d. Continue looping as long as i is less than or equal to N.
9. End Do-While Loop.
10. Print the final calculated sum.
11. Close the Scanner object.
12. End the program.