langs a-z

Task/Knuths-algorithm-S/CoffeeScript/knuths-algorithm-s-1.coffeescript

@@ -0,0 +1,31 @@
+s_of_n_creator = (n) ->
+  arr = []
+  cnt = 0
+  (elem) ->
+    cnt += 1
+    if cnt <= n
+      arr.push elem
+    else
+      pos = Math.floor(Math.random() * cnt)
+      if pos < n
+        arr[pos] = elem
+    arr.sort()
+
+sample_size = 3
+range = [0..9]
+num_trials = 100000
+
+counts = {}
+
+for digit in range
+  counts[digit] = 0
+
+for i in [1..num_trials]
+  s_of_n = s_of_n_creator(sample_size)
+  for digit in range
+    sample = s_of_n(digit)
+  for digit in sample
+    counts[digit] += 1
+
+for digit in range
+  console.log digit, counts[digit]