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Diffstat (limited to 'go/leap')
-rw-r--r-- | go/leap/README.md | 69 | ||||
-rw-r--r-- | go/leap/cases_test.go | 18 | ||||
-rw-r--r-- | go/leap/go.mod | 3 | ||||
-rw-r--r-- | go/leap/leap.go | 7 | ||||
-rw-r--r-- | go/leap/leap_test.go | 22 |
5 files changed, 119 insertions, 0 deletions
diff --git a/go/leap/README.md b/go/leap/README.md new file mode 100644 index 0000000..84ba774 --- /dev/null +++ b/go/leap/README.md @@ -0,0 +1,69 @@ +# Leap + +Given a year, report if it is a leap year. + +The tricky thing here is that a leap year in the Gregorian calendar occurs: + +```text +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. + +## 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][video]. + +[video]: http://www.youtube.com/watch?v=xX96xng7sAE + +You will see a `cases_test.go` file in this exercise. This holds the test +cases used in the `leap_test.go`. You can mostly ignore this file. + +However, if you are interested... we sometimes generate the test data from a +[cross language repository][problem-specifications-leap]. In that repo +exercises may have a [.json file][problem-specifications-leap-json] that +contains common test data. Some of our local exercises have an +[intermediary program][local-leap-gen] that takes the problem specification +JSON and turns in into Go structs that are fed into the `<exercise>_test.go` +file. The Go specific transformation of that data lives in the `cases_test.go` file. + +[problem-specifications-leap]: https://github.com/exercism/problem-specifications/tree/master/exercises/leap +[problem-specifications-leap-json]: https://github.com/exercism/problem-specifications/blob/master/exercises/leap/canonical-data.json +[local-leap-gen]: https://github.com/exercism/go/blob/master/exercises/leap/.meta/gen.go + + +## Coding the solution + +Look for a stub file having the name leap.go +and place your solution code in that file. + +## Running the tests + +To run the tests run the command `go test` from within the exercise directory. + +If the test suite contains benchmarks, you can run these with the `--bench` and `--benchmem` +flags: + + go test -v --bench . --benchmem + +Keep in mind that each reviewer will run benchmarks on a different machine, with +different specs, so the results from these benchmark tests may vary. + +## Further information + +For more detailed information about the Go track, including how to get help if +you're having trouble, please visit the exercism.io [Go language page](http://exercism.io/languages/go/resources). + +## Source + +JavaRanch Cattle Drive, exercise 3 [http://www.javaranch.com/leap.jsp](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. diff --git a/go/leap/cases_test.go b/go/leap/cases_test.go new file mode 100644 index 0000000..f9e8c04 --- /dev/null +++ b/go/leap/cases_test.go @@ -0,0 +1,18 @@ +package leap + +// Source: exercism/problem-specifications +// Commit: 18875ec Leap: Improve the specification so that code generation is more readable - … (#1468) +// Problem Specifications Version: 1.5.1 + +var testCases = []struct { + year int + expected bool + description string +}{ + {2015, false, "year not divisible by 4 in common year"}, + {1970, false, "year divisible by 2, not divisible by 4 in common year"}, + {1996, true, "year divisible by 4, not divisible by 100 in leap year"}, + {2100, false, "year divisible by 100, not divisible by 400 in common year"}, + {2000, true, "year divisible by 400 in leap year"}, + {1800, false, "year divisible by 200, not divisible by 400 in common year"}, +} diff --git a/go/leap/go.mod b/go/leap/go.mod new file mode 100644 index 0000000..bdbf06a --- /dev/null +++ b/go/leap/go.mod @@ -0,0 +1,3 @@ +module leap + +go 1.13 diff --git a/go/leap/leap.go b/go/leap/leap.go new file mode 100644 index 0000000..e56ff65 --- /dev/null +++ b/go/leap/leap.go @@ -0,0 +1,7 @@ +// leap implements IsLeapYear. +package leap + +// IsLeapYear returns if the year passed is a leap year. +func IsLeapYear(year int) bool { + return year%4 == 0 && (year%100 != 0 || year%400 == 0) +} diff --git a/go/leap/leap_test.go b/go/leap/leap_test.go new file mode 100644 index 0000000..eabd1f2 --- /dev/null +++ b/go/leap/leap_test.go @@ -0,0 +1,22 @@ +package leap + +import "testing" + +func TestLeapYears(t *testing.T) { + for _, test := range testCases { + observed := IsLeapYear(test.year) + if observed != test.expected { + t.Fatalf("IsLeapYear(%d) = %t, want %t (%s)", + test.year, observed, test.expected, test.description) + } + } +} + +// Benchmark 400 year interval to get fair weighting of different years. +func Benchmark400(b *testing.B) { + for i := 0; i < b.N; i++ { + for y := 1600; y < 2000; y++ { + IsLeapYear(y) + } + } +} |