From 741bec3efdf4bedf714a067e7fe3e6a20d9bcc23 Mon Sep 17 00:00:00 2001
From: Omar Boukli-Hacene <oboukli@users.noreply.github.com>
Date: Mon, 11 Sep 2023 22:10:17 +0200
Subject: [PATCH] Fibonacci sequence loops

---
 CMakeLists.txt                             |  4 ++
 benchmark/fibonacci_sequence_benchmark.cpp | 75 ++++++++++++++++++++++
 include/forfun/fibonacci_sequence.hpp      | 19 ++++++
 src/fibonacci_sequence.cpp                 |  9 +++
 test/fibonacci_sequence_test.cpp           | 17 +++++
 5 files changed, 124 insertions(+)
 create mode 100644 benchmark/fibonacci_sequence_benchmark.cpp
 create mode 100644 include/forfun/fibonacci_sequence.hpp
 create mode 100644 src/fibonacci_sequence.cpp
 create mode 100644 test/fibonacci_sequence_test.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1213412..dc5fc11 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,12 +27,14 @@ project(
 add_library(
   forfun
   SHARED
+  "include/forfun/fibonacci_sequence.hpp"
   "include/forfun/first_missing_positive.hpp"
   "include/forfun/fizzbuzz.hpp"
   "include/forfun/lru_cache.hpp"
   "include/forfun/palindrome.hpp"
   "include/forfun/palindromic_number.hpp"
   "include/forfun/sonar.hpp"
+  "src/fibonacci_sequence.cpp"
   "src/first_missing_positive.cpp"
   "src/fizzbuzz.cpp"
   "src/lru_cache.cpp"
@@ -132,6 +134,7 @@ target_link_libraries(
 find_package(Catch2 3 REQUIRED)
 add_executable(
   tests
+  "test/fibonacci_sequence_test.cpp"
   "test/first_missing_positive_test.cpp"
   "test/fizzbuzz_test.cpp"
   "test/palindromic_number_test.cpp"
@@ -154,6 +157,7 @@ find_package(nanobench CONFIG REQUIRED)
 add_executable(
   benchmark
   "benchmark/benchmark.cpp"
+  "benchmark/fibonacci_sequence_benchmark.cpp"
   "benchmark/first_missing_positive_benchmark.cpp"
   "benchmark/lru_cache_benchmark.cpp"
   "benchmark/palindrome_benchmark.cpp"
diff --git a/benchmark/fibonacci_sequence_benchmark.cpp b/benchmark/fibonacci_sequence_benchmark.cpp
new file mode 100644
index 0000000..f99a566
--- /dev/null
+++ b/benchmark/fibonacci_sequence_benchmark.cpp
@@ -0,0 +1,75 @@
+// Copyright (c) Omar Boukli-Hacene. All rights reserved.
+// Distributed under an MIT-style license that can be
+// found in the LICENSE file.
+
+// SPDX-License-Identifier: MIT
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <nanobench.h>
+
+inline constexpr int const f{514229};
+inline constexpr unsigned long const ful{f};
+
+static_assert(ful == f);
+
+TEST_CASE(
+    "fibonacci sequence loops benchmarking", "[benchmark][fibonacci_sequence]")
+{
+    using result_t = unsigned long;
+    static_assert(sizeof(result_t) >= 8);
+
+    ankerl::nanobench::Bench()
+        .title("Fibonacci sequence loops")
+
+        .run(
+            "Three variables",
+            []() {
+                result_t r{};
+                // clang-format off
+                for (auto i{0}, j{1}, tmp{0};
+                    i <= f;
+                    tmp = j + i, i = j, j = tmp)
+                {
+                    r += i;
+                }
+                // clang-format on
+                ankerl::nanobench::doNotOptimizeAway(r);
+            })
+
+        .run(
+            "Two variables",
+            []() {
+                result_t r{};
+                for (auto i{0}, j{1}; i <= f; j += i, i = j - i)
+                {
+                    r += i;
+                }
+                ankerl::nanobench::doNotOptimizeAway(r);
+            })
+
+        .run(
+            "Two unsigned long variables",
+            []() {
+                result_t r{};
+                for (auto i{0ul}, j{1ul}; i <= ful; j += i, i = j - i)
+                {
+                    r += i;
+                }
+                ankerl::nanobench::doNotOptimizeAway(r);
+            })
+
+        .run(
+            "Two variables by Creel",
+            []() {
+                result_t r{};
+                // Source: https://youtu.be/IZc4Odd3K2Q?t=949
+                for (auto i{0}, j{1}; i <= f; j = (i += j) - j)
+                {
+                    r += i;
+                }
+                ankerl::nanobench::doNotOptimizeAway(r);
+            })
+
+        ;
+}
diff --git a/include/forfun/fibonacci_sequence.hpp b/include/forfun/fibonacci_sequence.hpp
new file mode 100644
index 0000000..fa38272
--- /dev/null
+++ b/include/forfun/fibonacci_sequence.hpp
@@ -0,0 +1,19 @@
+// Copyright (c) Omar Boukli-Hacene. All rights reserved.
+// Distributed under an MIT-style license that can be
+// found in the LICENSE file.
+
+// SPDX-License-Identifier: MIT
+
+/// Problem source:
+/// https://en.wikipedia.org/wiki/Fibonacci_sequence
+
+#ifndef FORFUN_FIBONACCI_SEQUENCE_HPP_
+#define FORFUN_FIBONACCI_SEQUENCE_HPP_
+
+namespace forfun::fibonacci::sequence {
+
+// See benchmark/fibonacci_benchmark.cpp
+
+} // namespace forfun::fibonacci::sequence
+
+#endif // FORFUN_FIBONACCI_SEQUENCE_HPP_
diff --git a/src/fibonacci_sequence.cpp b/src/fibonacci_sequence.cpp
new file mode 100644
index 0000000..d6c388a
--- /dev/null
+++ b/src/fibonacci_sequence.cpp
@@ -0,0 +1,9 @@
+// Copyright (c) Omar Boukli-Hacene. All rights reserved.
+// Distributed under an MIT-style license that can be
+// found in the LICENSE file.
+
+// SPDX-License-Identifier: MIT
+
+#include "forfun/fibonacci_sequence.hpp"
+
+// See benchmark/fibonacci_sequence_benchmark.cpp
diff --git a/test/fibonacci_sequence_test.cpp b/test/fibonacci_sequence_test.cpp
new file mode 100644
index 0000000..e9477a4
--- /dev/null
+++ b/test/fibonacci_sequence_test.cpp
@@ -0,0 +1,17 @@
+// Copyright (c) Omar Boukli-Hacene. All rights reserved.
+// Distributed under an MIT-style license that can be
+// found in the LICENSE file.
+
+// SPDX-License-Identifier: MIT
+
+#include <catch2/catch_test_macros.hpp>
+
+#include "forfun/fibonacci_sequence.hpp"
+
+TEST_CASE("fibonacci_sequence")
+{
+    SECTION("Loops")
+    {
+        SKIP("See benchmark/fibonacci_sequence_benchmark.cpp");
+    }
+}