Avatar of shmibs

shmibs's solution

to Leap in the Nim Track

Published at Jul 13 2018 · 0 comments
Instructions
Test suite
Solution

Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

Given a year, report if it is a leap year.

The tricky thing here is that a leap year in the Gregorian calendar occurs:

on every year that is evenly divisible by 4
  except every year that is evenly divisible by 100
    unless the year is also evenly divisible by 400

For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap year, but 2000 is.

If your language provides a method in the standard library that does this look-up, pretend it doesn't exist and implement it yourself.

Notes

Though our exercise adopts some very simple rules, there is more to learn!

For a delightful, four minute explanation of the whole leap year phenomenon, go watch this youtube video.

Running the tests

To compile and run the tests, just run the following in your exercise directory:

$ nim c -r leap_test.nim

Submitting Exercises

Note that, when trying to submit an exercise, make sure the solution is in the $EXERCISM_WORKSPACE/nim/leap directory.

You can find your Exercism workspace by running exercism debug and looking for the line that starts with Exercises Directory.

For more detailed information about running tests, code style and linting, please see the help page.

Source

JavaRanch Cattle Drive, exercise 3 http://www.javaranch.com/leap.jsp

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

leap_test.nim

import unittest
from leap import isLeapYear

suite "Leap":

  test "year not divisible by 4: common year":
    check isLeapYear(2015) == false
   
  test "year divisible by 4, not divisible by 100: leap year":
    check isLeapYear(1996) == true
  
  test "year divisible by 100, not divisible by 400: common year":
    check isLeapYear(2100) == false
  
  test "year divisible by 400: leap year":
    check isLeapYear(2000) == true
proc isLeapYear*(year: int): bool =
    return year mod 4 == 0 and year mod 100 != 0 or year mod 400 == 0

Community comments

Find this solution interesting? Ask the author a question to learn more.

What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?