June 2018 Update

Task/Middle-three-digits/Elena/middle-three-digits.elena

@@ -0,0 +1,29 @@
+import system'routines.
+import extensions.
+
+middleThreeDigits = (:n)<int>
+[
+    literal s := n absolute; literal.
+    int len := s length.
+    if(len<3)
+    [
+        InvalidArgumentException new:"n must have 3 digits or more"; raise
+    ];
+    if(len isEven)
+    [
+        InvalidArgumentException new:"n must have an odd number of digits"; raise
+    ].
+
+    int mid := len / 2.
+
+    ^ s Substring(mid-1,3).
+].
+
+program =
+[
+    (123, 12345, 1234567, 987654321, 10001, -10001, -123, -100, 100, -12345, 1, 2, -1, -10, 2002, -2002, 0)
+    forEach(:n)
+    [
+        console printLine("middleThreeDigits(",n,"):",middleThreeDigits eval(n) | if(:e)(e message))
+    ]
+].