Data commit

Task/Range-extraction/Nim/range-extraction.nim

@@ -0,0 +1,30 @@
+import parseutils, re, strutils, sequtils
+
+proc extractRange(input: string): string =
+  var list = input.replace(re"\s+").split(',').map(parseInt)
+  var ranges: seq[string]
+  var i = 0
+  while i < list.len:
+    var first = list[i] # first element in the current range
+    var offset = i
+    while True: # skip ahead to the end of the current range
+      if i + 1 >= list.len:
+        # reached end of the list
+        break
+      if list[i + 1] - (i + 1) != first - offset:
+        # next element isn't in the current range
+        break
+      i.inc
+    var last = list[i] # last element in the current range
+    case last - first
+      of 0: ranges.add($first)
+      of 1: ranges.add("$1,$2".format(first, last))
+      else: ranges.add("$1-$2".format(first, last))
+    i.inc
+  return ranges.join(",")
+
+echo("""
+    0,  1,  2,  4,  6,  7,  8, 11, 12, 14,
+   15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
+   25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
+   37, 38, 39""".extractRange)