HW2 (due Sat. 28-Jan, 8pm)

From the syllabus: Each CS Academy assignment has a required number of "stars" in several sections, listed like this:
"Section Exercises: ⭐ 0 / 11."
Unless otherwise specified, each star is worth the same percentage of your homework score, up to 100%. If you complete fewer than the required number of stars in a section, you will receive a score equal to the percentage of required stars you completed. For example, if there are 16 required stars and you complete 8, you will receive 50%. If you complete all of the required stars you will receive 100% on the assignment. Each star you complete over the required number for that section is worth 0.5 percentage points of bonus on the assignment. Thus, if there are 16 required stars and you complete 19, you will receive a 101.5% on the assignment. Unless otherwise specified, bonus points cannot bring your score above a 105% per assignment. Stars from CTs are ineligible for bonus points.

Also, beginning this week, you cannot earn more than 5 bonus points from stars in Additional Practice exercises. (This is just so you don't use them to dodge the required problems.)

A green checkmark next to a problem (in CS Academy) means it has autograded correctly and you are done. No green checkmark means it's not done yet. If you believe you should have received a green checkmark, be sure to review your work, and be sure that you hit the "check" button after the "run" button to submit it. The "check" button runs your code against additional hidden test cases which you must pass in order to receive credit. It's your responsibility to properly submit and be aware of whether you have received green-checkmark credit for your work! There is generally no partial credit for autograded problems.

Important Notes:

Aside from problems we fully solve in lecture or recitation, homework is fully solo. You must not collaborate with anyone (besides current course TA's and faculty) in any way. See the syllabus for more details.
Do not hardcode to the test cases in your solutions.
As for exercises marked with ✓:
- We plan to cover these in lecture or recitation. You may take notes, and it is fine if your solution looks like ours, but we strongly discourage you from simply copying what we type. Instead, take notes on the approach and try to recreate the solution yourself.
- For the best learning experience, we recommend that you do not attempt these exercises before we cover them in lecture or recitation.
- The problems with checkmarks are somewhat subject to change and lecture timing. Sometimes we may cover one or two more, or we may change which one we cover, but we will try not to.
We will not grade your code for style this week, but you should begin to write your code with good style. We will almost certainly grade for style in week 3!
Do not use string indexing, string methods, lists, list indexing, or recursion this week.

In CS Academy, complete the required number of stars from each section below.
For each section, we list the number of required and available stars. For example, this means 2 out of 4 stars are required from a section: "2/4 ⭐ required"
The number of stars available for each problem is in parentheses. For example, this means you get 2 stars for solving a problem: "(2)"

Unit 2: Loops
- 2.2.6 Code Tracing Exercises: 2/2 ⭐ required
- 2.2.7 Guided Exercises: 5/5 ⭐ required
  - ✓isPrime (1)
  - ✓nthPrime (1)
  - ✓reverseNumber (1)
  - ✓mostFrequentDigit (1)
  - ✓hasConsecutiveDigits (1)
- 2.2.8 Section Exercises: 8/12 ⭐ required
  - nthEmirpPrime (1)
  - nthEinNumber (1)
  - babylonianSquareRootIterations (1)
  - stepsToReach495 (2)
  - occursIn (2)
  - isRotation (2)
  - isLangfordPairing (3)
- 2.2.9 Honors Exercises: 7/11 ⭐ required
  - longestDigitRun (3)
  - integral (4)
  - carrylessMultiply (4)
- 2.2.11 Additional Practice Exercises: 0/22 ⭐ required
  - (None required, but you can earn up to 5 bonus points here)
  - (See details above for how bonus points are calculated)