example: add artihmetic mode example from rosetta code

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/examples/rosettacode/arithmetic_mode.nit b/examples/rosettacode/arithmetic_mode.nit
new file mode 100644 (file)
index 0000000..362372e
--- /dev/null
+++ b/examples/rosettacode/arithmetic_mode.nit
@@ -0,0 +1,33 @@
+#!/usr/bin/env nit
+#
+# This file is part of NIT ( http://www.nitlanguage.org ).
+# This program is public domain
+
+# Task: Arithmetic mode
+# SEE: <http://rosettacode.org/wiki/Averages/Mode>
+module arithmetic_mode
+
+# Computes the mode or the `array` values.
+#
+# FIXME: Only the first mode will be returned, should we return an array of modes?
+fun mode(array: Array[Int]): nullable Int do
+       var seen = new HashMap[Int, Int]
+       for i in array do
+               if not seen.has_key(i) then seen[i] = 0
+               seen[i] += 1
+       end
+       var max_key = null
+       var max_val = 0
+       for k, v in seen do
+               if v > max_val then
+                       max_key = k
+                       max_val = v
+               end
+       end
+       return max_key
+end
+
+print mode([1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17]) or else "null"
+print mode([1, 1, 2, 4, 4]) or else "null"
+print mode([1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17]) or else "null"
+print mode([1, 1, 2, 4, 4]) or else "null"

diff --git a/tests/sav/arithmetic_mode.res b/tests/sav/arithmetic_mode.res
new file mode 100644 (file)
index 0000000..290a7d5
--- /dev/null
+++ b/tests/sav/arithmetic_mode.res
@@ -0,0 +1,4 @@
+6
+1
+6
+1