Write a program that reads doubles, find the square root for each number also yo

Question

Write a program that reads doubles, find the square root for each number also you must list all prime factors.
Sample:
Input must be entered such a format :
Enter numbers (0 for Exit): 16 8 9 12 0
Output must be:
The square root of 16 is 4
Prime factors of 16 are 2
The square root of 8 is 2.8
Prime factors of 8 are 2
The square root of 9 is 3
Prime factors of 9 are 3
The square root of 12 is 3.46
Prime factors of 12 are 2, 3
You are not allowed to use Math.sqrt().

just use import java.util.Scanner;
p.class
p.class static void main
...

Explanation / Answer

Hi, I think you'll find this follows your requirements. Give it a read and test it out a couple of times to understand how it works. I commented the important stuff. Also, I use a little trick in printing out the square root because doubles are ridiculous to print with 6 - 10 digits of precision, so that's a cheap trick to cut it to smaller precision without using java Math methods.

I hope it helps, please remember to rate :)

import java.util.Scanner;

public class MyClass {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double number;
       
        System.out.print(" Enter numbers (0 for Exit): ");
        do
        {
            number = scanner.nextDouble();
            if(number != 0)
            {
                // ============= COMPUTING SQUARE ROOT ===============
                // get Square root using Babylonian method
                double estimate=number;
                double divisor=2;
                for(int i=0; i<100; i++)
                {
                    estimate=number/divisor;      
                    estimate=(estimate+divisor)/2; //find average estimate & divisor
                    divisor=estimate;
                }
                double sqrt = estimate;
               
                // if sqrt is a full integer - print it as is
                if(sqrt % 1 == 0)
                {
                    System.out.println("The square root of " + (int)number
                        + " is " + (int)sqrt );
                }
                // else, the sqrt to limit it to 2 decimal places
                else
                {
                    // scale it
                    int x = (int)(sqrt * 100.0);
                    double formatedSqrt = ((double)x)/100.0;
                    System.out.println("The square root of " + (int)number
                            + " is " + formatedSqrt );
                }
               
                // ============= COMPUTING PRIME FACTORS ===============
                // List all prime factors of number
                System.out.print("Prime factors of " + (int)number + " are ");
                for(int i = 2; i <= number; i++)
                {
                    if(number % i == 0)
                    {
                        if(i == 2)
                            System.out.print(" " + i);
                        else
                        {
                            boolean isPrime = true;
                            for(int j = 2; j < i; j++)
                            {
                                if(i % j == 0)
                                    isPrime = false;
                            }
                            if(isPrime)
                                System.out.print(" " + i);
                        }
                    }
                }
                System.out.print(" ");  
            }
           
        }while(number != 0);
       
    }// end of main method
}

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