Important Notice:

Practice-It will be discontinued as of November 1st, 2024. After this date, the website will remain online for a transitional period, but login will be restricted to University of Washington NetID authentication. This marks the next phase towards the platform's full retirement. Thank you for your use and support of the application over the years.

If you are looking for an alternative, a similar tool, CodeStepByStep, was developed independently by the original author of Practice-It, and is available at codestepbystep.com**

logo Practice-It logo

Main Page → Problems → Solve a Problem

ones

Language/Type: Java BigInteger
Author: Marty Stepp (on 2013/01/07)

Given any integer 0 < n ≤ 10000 not divisible by 2 or 5, some multiple of n is a number which in decimal notation is a sequence of 1s. Write a method named ones that accepts an integer n as a parameter and returns how many digits are in the smallest such multiple of n. For example, the call of ones(3) returns 3 because the smallest multiple of 3 that consists entirely of 1s is 111, which is 3 digits long. Similarly, the call of ones(7) returns 6 because the smallest such multiple of 7 is 111111. You may assume that the integer n passed is not divisible by 2 or 5 and is in the proper specified range.

Type your solution here:


This is a method problem. Write a Java method as described. Do not write a complete program or class; just the method(s) above.

You must log in before you can solve this problem.


Log In

If you do not understand how to solve a problem or why your solution doesn't work, please contact your TA or instructor.
If something seems wrong with the site (errors, slow performance, incorrect problems/tests, etc.), please

Is there a problem? Contact a site administrator.