1 ) Write a recursive method called descend that prints the numbers 1…n in desce

Question

1 ) Write a recursive method called descend that prints the numbers 1…n in descending order. Your main method will need to read n from the user, then call method descend with the number read.

2) Write a recursive method called exp to perform exponentiation return x, assuming n >= 0. Your main method will need to read x and n from a file, then call method exp with the input read. Print the result of x after each recursive call.

This is what i have so far. I just dont get part 2.

import java.util.Scanner;

public class Recursion {

   public static void main(String[] args){
  
       Scanner scn = new Scanner(System.in);
       int n = 0;
   System.out.println("Enter Number");
       n = scn.nextInt();
       descend(n);
   }
  
  
  

   public static int descend(int n){
           if(n==0){
               return n;
           }
           else{
               System.out.println(n);
               descend(n-1);}
           return n;
   }

Explanation / Answer

// include the required header file
import java.util.*;
import java.io.*;

public class Recursion {

    public static void main(String[] args){
        int x,n;
        BufferedReader br = null;
       try {
           String sCurrentLine;
           //read first line frm file
           br = new BufferedReader(new FileReader("input.txt"));
           while ((sCurrentLine = br.readLine()) != null) {
                //spilt the line read using "^" as tokenizer
                String tokens[]=sCurrentLine.split(" ");
                //store first token as x(base)
                x=Integer.parseInt(tokens[0]);
                //store second token as n(power)
                n=Integer.parseInt(tokens[1]);
                //call exp function
                System.out.println(x+"^"+n+" : "+exp(x,n));
           }
       } catch (IOException e) {
           System.out.println("Unable to able file!!");
       }
    }
  
//fiunction to calculate exp
public static int exp(int base, int power)
{
      //return 1 if power is 0
      if(power==0)
      {
           return 1;
      }
      //else multiply base with power
      else
      {
          int result=base*exp(base, power-1);
          System.out.println(result);
          return result;
      }

    
}
}

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.