Question

Need to write a java program from pseudo code, I’ve got a bit of code written, its not working and I’m not sure if i’ve done it right or not as I simply tried to follow the pseudo code –

• Read i
• While i > 0
• Print the remainder i % 2

• Set i to i / 2

  import java.util.Scanner;
  
  import java.util.Scanner;
  
  public class InputLoop
  {
      public static void main(String[] args)
      {
          int i = 0;
          Scanner scan = new Scanner(System.in);
          System.out.println("Enter an integer");
          while (!scan.hasNextInt()) // while non-integers are present
          {
              scan.next();
              System.out.println ("Bad input. Enter an integer.");
          }
          while (i>0) // while greater than 0
          {
              int input = scan.nextInt();
              System.out.println (i%2);
              i = (i/2);
          }
  
      }
  }
  

Answer 1

Frankly speaking, you didn't(Ah missed it earlier) exactly followed the pseudo-code. The pseudo code tells you to read i, whereas you are reading input. That’s one problem.

Second problem is that, you should read the input outside the while loop where you are doing the processing with the input. That is the 2nd thing you didn’t followed.

Currently your while loop is: –

    while (i>0) // while greater than 0
    {
        int input = scan.nextInt();
        System.out.println (i%2);
        i = (i/2);
    }

This is read input from user on every iteration which you don’t want.

So, you need to modify your code a little bit: –

int i = scan.nextInt();  // Read input outside the while loop

while (i>0) // while greater than 0
{      
    System.out.println (i%2);
    i = i/2;   // You don't need a bracket here
}