Data commit

Task/Entropy/Crystal/entropy.crystal

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+# Method to calculate sum of Float64 array
+def sum(array : Array(Float64))
+  res = 0
+  array.each do |n|
+    res += n
+  end
+  res
+end
+
+# Method to calculate which char appears how often
+def histogram(source : String)
+  hist = {} of Char => Int32
+  l = 0
+  source.each_char do |e|
+    if !hist.has_key? e
+      hist[e] = 0
+    end
+    hist[e] += 1
+  end
+  return Tuple.new(source.size, hist)
+end
+
+# Method to calculate entropy from histogram
+def entropy(hist : Hash(Char, Int32), l : Int32)
+  elist = [] of Float64
+  hist.each do |el|
+    v = el[1]
+    c = v / l
+    elist << (-c * Math.log(c, 2))
+  end
+  return sum elist
+end
+
+source = "1223334444"
+hist_res = histogram source
+l = hist_res[0]
+h = hist_res[1]
+puts ".[Results]."
+puts "Length: " + l.to_s
+puts "Entropy: " + (entropy h, l).to_s