Practice-It! logo

BJP3 Exercise 12.3: writeSequence

Added by: Marty Stepp on 2013/04/01
Language: Java
Keywords: recursion

Write a method writeSequence that accepts an integer n as a parameter and prints a symmetric sequence of n numbers with descending integers ending in 1 followed by ascending integers beginning with 1, as in the table below:

Call Output
writeSequence(1); 1
writeSequence(2); 1 1
writeSequence(3); 2 1 2
writeSequence(4); 2 1 1 2
writeSequence(5); 3 2 1 2 3
writeSequence(6); 3 2 1 1 2 3
writeSequence(7); 4 3 2 1 2 3 4
writeSequence(8); 4 3 2 1 1 2 3 4
writeSequence(9); 5 4 3 2 1 2 3 4 5
writeSequence(10); 5 4 3 2 1 1 2 3 4 5

Notice that for odd numbers the sequence has a single 1 in the middle while for even values it has two 1s in the middle.

Your method should throw an IllegalArgumentException if passed a value less than 1. A client using this method would have to call println to complete the line of output.

Method problem: For this problem, you are supposed to write a Java method as described. You should not write a complete Java class; just write the method(s) described in the problem statement.

You must log in before you can solve this problem.

user
Log In


indent Re-indent

If you do not understand how to solve a problem or why your solution code doesn't work, please contact your TA or instructor.

If something seems wrong with the Practice-It system itself (errors, slow performance, incorrect problem descriptions/tests, etc.), please contact us.

Is there a problem?
Contact a Practice-It administrator.