public class Factors {
    private int start = 1, end;

    public static void main(String[] args) {
        Factors findfactors = new Factors();

        findfactors.getRange();
        findfactors.listPrimeFactorizations();
    }

    // Prompt the user for input. Save the input with the
    // appropriate variables.
    public void getRange() {
        // start = Starting number 1
        start = Prompt.getValue("Enter a starting integer from 2 to 100 -> ");

        while (start > 100 || start < 2) {
            start = Prompt.getValue("Please enter a valid starting integer from 2 to 100 -> ");
        }

        // end = Starting number 2
        end = Prompt.getValue("Enter an ending integer from " + start + " to 999 -> ");
        while (end < start || end > 999) {
            end = Prompt.getValue("Please enter a valid ending integer from " + start + " to 999 -> ");
        }
    }

    /**
     * List the integers, from start to end. Show the prime factorization for
     * each integer in the list. Call printFactorization for each integer in the
     * list.
     */
    public void listPrimeFactorizations() {

        for (; start <= end; start++) {
            // This loop checks for the amount of numbers left to factor
            printFactorization(start);
        }

    }

    // Print the prime factorization for the positive
    // integer passed in the parameter list.
    public void printFactorization(int num) {

        boolean firstTime = true; // true if 1st print

        int i = num;
        int base = 2;

        System.out.print(num + " = ");

        while (base <= num) {

            // check if divisible by the base with no remainder
            while (i % base == 0) {
                i = i / base;

                if (firstTime == false) {
                    System.out.print(" * ");
                }

                System.out.print(base);
                firstTime = false;
                base = 2; // reset
            }

            base++;
        }

        System.out.println();
    }

}