Data commit

Task/Five-weekends/Groovy/five-weekends-1.groovy

@@ -0,0 +1,17 @@
+enum Day {
+    Sun, Mon, Tue, Wed, Thu, Fri, Sat
+    static Day valueOf(Date d) { Day.valueOf(d.format('EEE')) }
+}
+
+def date = Date.&parse.curry('yyyy-M-dd')
+def isLongMonth = { firstDay -> (firstDay + 31).format('dd') == '01'}
+
+def fiveWeekends = { years ->
+    years.collect { year ->
+        (1..12).collect { month ->
+            date("${year}-${month}-01")
+        }.findAll { firstDay ->
+            isLongMonth(firstDay) && Day.valueOf(firstDay) == Day.Fri
+        }
+    }.flatten()
+}

Task/Five-weekends/Groovy/five-weekends-2.groovy

@@ -0,0 +1,5 @@
+def ym = { it.format('yyyy-MM') }
+def years = 1900..2100
+def fiveWeekendMonths = fiveWeekends(years)
+println "Number of five weekend months: ${fiveWeekendMonths.size()}"
+fiveWeekendMonths.each { println (ym(it)) }

Task/Five-weekends/Groovy/five-weekends-3.groovy

@@ -0,0 +1,4 @@
+def yearsWith = fiveWeekendMonths.collect { it.format('yyyy') as int } as Set
+def yearsWithout = (years as Set) - yearsWith
+println "\nNumber of years without a five weekend month: ${yearsWithout.size()}"
+yearsWithout.each { println it }