How to find square root, log recursively???

Question

I need to find the square root of a number entered recursively and log as well. Your help would be greatly appreciated. Thanks in advance!
import java.io.*;
/**Class provides recursive versions
* of simple arithmetic operations.
public class Ops2
     private static BufferedReader in = null;
     /**successor, return n + 1*/
     public static int suc(int n)
          return n + 1;
     /**predecessor, return n - 1*/
     public static int pre(int n)
          if (n == 0)
               return 0;
          else
               return n - 1;
     /**add two numbers entered*/
     public static int add(int n, int m)
          if (m == 0)
               return n;
          else
               return suc(add(n, pre(m)));
     /**subtract two numbers entered*/
     public static int sub(int n, int m)
          if (n < m)
               return 0;
          else if (m == 0)
               return n;
          else
               return pre(sub(n, pre(m)));
     /**multiply two numbers entered*/
     public static int mult(int n, int m)
          if (m == 0)
               return 0;
          else
               return add(mult(n, pre(m)), n);
     /**divide two numbers entered*/
     public static int div(int n, int m)
          if (n < m)
               return 0;
          else
               return suc(div(sub(n, m), m));
     /**raise first number to second number*/
     public static int exp(int n, int m)
          if (m == 0)
               return 1;
          else
               return mult(exp(n, pre(m)), n);
     /**log of number entered*/
     public static int log(int n)
          if (n < 2)
               return 0;
          else
               return suc(log(div(n, 2)));
     /**square root of number entered*/
     public static int sqrt(int n)
          if (n == 0)
               return 0;
          else
               return sqrt(div(n, ));
     /**remainder of first number entered divided by second number*/
     public static int mod(int n, int m)
          if (n < m)
               return 0;
          else
               return mod(div(n, pre(m)), m);
     public static void prt(String s)
          System.out.print(s);
     public static void prtln(String s)
          System.out.println(s);
     public static void main(String [ ] args)
          prtln("Welcome to the amazing calculator");
          prtln("It can add, multiply and do powers for");
          prtln("naturals (including 0). Note that all the");
          prtln("HARDWARE does is add 1 or substract 1 to any number!!");
          in = new BufferedReader(new InputStreamReader ( System.in ) );
          int It;
          while ( (It = getOp()) >= 0)
               prt("" + It + "\n");
        private static int getOp( )
        int first, second;
        String op;
        try
            System.out.println( "Enter operation:" );
            do
                op = in.readLine( );
            } while( op.length( ) == 0 );
         System.out.println( "Enter first number: " );
            first = Integer.parseInt( in.readLine( ) );
            System.out.println( "Enter second number: " );
            second = Integer.parseInt( in.readLine( ) );
         prtln("");
         prt(first + " " + op + " " + second + " = ");
            switch( op.charAt( 0 ) )
              case '+':
                return add(first, second);
              case '-':
                   return sub(first, second);
              case '*':
                return mult(first, second);
              case '/':
                   return div(first, second);
              case '^':
                return exp(first, second);
              case 'v':
                   return log(first);
              case 'q':
                   return sqrt(first);
              case '%':
                   return mod(first, second);
              case 's':
                   return suc(first);
              case 'p':
                   return pre(first);
              default:
                System.err.println( "Need +, *, or ^" );
                return -1;
        catch( IOException e )
            System.err.println( e );
            return  0;
}

Answer 1

Hi,
Is there any one to make a program for me in Turbo
C++ for Dos, which can calculate the square root of
any number without using the sqrt( ) or any ready
made functions.
The program should calculate the s.root of the number
by a formula or procedure defined by the user
(programmer).
Thanks.This is a Java forum!
If you want Java help:
1. Start your own thread.
2. Use code tags (above posting box) if you post code.
3. No one will write the program for you. We will help by answering your questions and giving advice on how to fix problems in code you wrote.
4. The formula you need to implement is given above by dizzy.