/*
 * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
 * Date: 2022-03-02
 * Assignment: #1 Question 1
 * Description: This program is used to calculate the sum and average of the numbers.
 * Input: The numbers
 * Output: The sum and average of the numbers
 * Version: 1.0
 */
public class SumAndAverage {
    public static void main(String[] args) {
        int sum = 0; // Store the accumulated sum init to 0
        double average; // average in double
        int lowerbound = 1; // The lowerbound to sum
        int upperbound = 100; // The upperbound to sum

        // Use a for-loop to sum from lowerbound to upperbound
        for (int number = lowerbound; number <= upperbound; number++) {
            // add only odds number
            if (number % 2 != 0) {
                sum += number;
            }
        }

        // Compute average in double. Beware that int/int produces int.
        average = (double) sum / (upperbound - lowerbound + 1);

        // Print sum and average
        System.out.println("The sum is " + sum);
        System.out.println("The average is " + average);

        // 6.1 while loop
        System.out.println("---- While-loop:");
        sum = 0;
        int number = lowerbound;
        while (number <= upperbound) {
            // only add number that is divisible by 7
            if (number % 7 == 0) {
                sum += number;
            }
            number++;
        }

        // Compute average in double. Beware that int/int produces int.
        average = (double) sum / (upperbound - lowerbound + 1);

        // Print sum and average
        System.out.println("The sum is " + sum);
        System.out.println("The average is " + average);

        // 6.2 do-while
        System.out.println("---- Do-while:");
        sum = 0; // Reset sum
        number = lowerbound;
        do {
            // sum of squares of number
            sum += number * number;
            number++;
        } while (number <= upperbound);

        // Compute average in double. Beware that int/int produces int.
        average = (double) sum / (upperbound - lowerbound + 1);

        // Print sum and average
        System.out.println("The sum is " + sum);
        System.out.println("The average is " + average);

    }
}