Printing out the relative lengths of the subdivisions on a ruler.

Ruler.java

public class Ruler {
 
   public static void main(String[] args) {
      int N = Integer.parseInt(args[0]);
 
      // ruler of order 0
      String ruler = " ";
 
      // repeat N times
      for (int i = 1; i <= N; i++) {
 
         // concatenate a ruler of order 0, the number i, and a ruler of order 0
         ruler = ruler + i + ruler;
 
         // print out the final result
         System.out.println(ruler);
      }
   }
}
 

output

$ java Ruler 5
 1 
 1 2 1 
 1 2 1 3 1 2 1 
 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 
 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 

Questions answered by this page:

Recurrence relation that describes the length of a ruler Prints the relative lengths of the subdivisions on a ruler.