A-M baby

Task/Hailstone-sequence/Groovy/hailstone-sequence-1.groovy

@@ -0,0 +1,8 @@
+def hailstone = { long start ->
+    def sequence = []
+    while (start != 1) {
+        sequence << start
+        start = (start % 2l == 0l) ? start / 2l : 3l * start + 1l
+    }
+    sequence << start
+}

Task/Hailstone-sequence/Groovy/hailstone-sequence-2.groovy

@@ -0,0 +1,7 @@
+def sequence = hailstone(27)
+assert sequence.size() == 112
+assert sequence[0..3] == [27, 82, 41, 124]
+assert sequence[-4..-1] == [8, 4, 2, 1]
+
+def results = (1..100000).collect { [n:it, size:hailstone(it).size()] }.max { it.size }
+println results