Data commit

Task/Combinations-with-repetitions/CoffeeScript/combinations-with-repetitions.coffee

@@ -0,0 +1,12 @@
+combos = (arr, k) ->
+  return [ [] ] if k == 0
+  return [] if arr.length == 0
+
+  combos_with_head = ([arr[0]].concat combo for combo in combos arr, k-1)
+  combos_sans_head = combos arr[1...], k
+  combos_with_head.concat combos_sans_head
+
+arr = ['iced', 'jam', 'plain']
+console.log "valid pairs from #{arr.join ','}:"
+console.log combos arr, 2
+console.log "#{combos([1..10], 3).length} ways to order 3 donuts given 10 types"