Data commit

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

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