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# 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``````