lunks · August 13, 2024 16:12 · Aug 13, 2024 · Aug 13, 2024
diff --git a/bench.exs b/bench.exs
@@ -0,0 +1,38 @@
+defmodule BenchmarkReduceWhile do
+  def has_duplicates?(list) do
+    Enum.reduce_while(list, %MapSet{}, fn x, seen ->
+      if MapSet.member?(seen, x) do
+        {:halt, true}
+      else
+        {:cont, MapSet.put(seen, x)}
+      end
+    end) || false
+  end
+end
+
+defmodule BenchmarkRecursion do
+  def has_duplicates?(list), do: has_duplicates?(list, %MapSet{})
+
+  defp has_duplicates?([], _), do: false
+
+  defp has_duplicates?([head | tail], seen) do
+    MapSet.member?(seen, head) || has_duplicates?(tail, MapSet.put(seen, head))
+  end
+end
+
+defmodule BenchmarkTest do
+  def run do
+    list = Enum.to_list(1..10000) ++ [5000]
+
+    Benchee.run(
+      %{
+        "reduce_while" => fn -> BenchmarkReduceWhile.has_duplicates?(list) end,
+        "recursion" => fn -> BenchmarkRecursion.has_duplicates?(list) end
+      },
+      time: 20,
+      warmup: 5
+    )
+  end
+end
+
+BenchmarkTest.run()
diff --git a/result.txt b/result.txt
@@ -0,0 +1,29 @@
+Operating System: Linux
+CPU Information: AMD Ryzen Threadripper 3970X 32-Core Processor
+Number of Available Cores: 32
+Available memory: 16 GB
+Elixir 1.16.2
+Erlang 26.2.5
+JIT enabled: true
+
+Benchmark suite executing with the following configuration:
+warmup: 5 s
+time: 20 s
+memory time: 0 ns
+reduction time: 0 ns
+parallel: 1
+inputs: none specified
+Estimated total run time: 50 s
+
+Benchmarking recursion ...
+Benchmarking reduce_while ...
+Calculating statistics...
+Formatting results...
+
+Name                   ips        average  deviation         median         99th %
+recursion           404.36        2.47 ms    ±13.41%        2.38 ms        3.52 ms
+reduce_while        372.01        2.69 ms    ±12.97%        2.53 ms        3.65 ms
+
+Comparison: 
+recursion           404.36
+reduce_while        372.01 - 1.09x slower +0.22 ms
No results found