Merge pull request JuliaLang#16 from andrej-makarov-skrt/ex-leap

Add exercise: leap

config.json

@@ -5,7 +5,15 @@
   "active": false,
   "test_pattern": "TODO",
   "exercises": [
-
+		{
+      "slug": "leap",
+      "difficulty": 1,
+      "topics": [
+        "control-flow (conditionals)",
+				"integers", 
+				"mathematics"
+      ]
+    }
   ],
   "deprecated": [
 

exercises/leap/example.jl

@@ -0,0 +1,5 @@
+# Leap 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
+is_leap_year(year::Int) = (year % 100 != 0 && year % 4 == 0) || (year % 400 == 0)
+

exercises/leap/leap.jl

@@ -0,0 +1,4 @@
+function is_leap_year(year::Int)
+
+end
+

exercises/leap/runtests.jl

@@ -0,0 +1,20 @@
+using Base.Test
+
+include("leap.jl")
+
+@testset "Year not divisible by 4: common year" begin
+  @test !is_leap_year(2015)
+end
+
+@testset "Year divisible by 4, not divisible by 100: leap year" begin
+  @test is_leap_year(2016)
+end
+
+@testset "Year divisible by 100, not divisible by 400: common year" begin
+  @test !is_leap_year(2100)
+end
+
+@testset "Year divisible by 400: leap year" begin
+  @test is_leap_year(2000)
+end
+