Restructure code and files

Isolate tests from algorithm code files

.editorconfig

@@ -1,6 +1,6 @@
 root = true
 
-[*.{c,cpp,h}]
+[*.{c,cpp,h,hpp}]
 charset = utf-8
 end_of_line = lf
 indent_size = 4

src/fizzbuzz.hpp

@@ -0,0 +1,45 @@
+// 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://imranontech.com/2007/01/24/using-fizzbuzz-to-find-developers-who-grok-coding/
+///
+/// Original problem text:
+/// Write a program that prints the numbers from 1 to 100. But for multiples of
+/// three print "Fizz" instead of the number and for the multiples of five
+/// print "Buzz". For numbers which are multiples of both three and five print
+/// "FizzBuzz".
+
+#ifndef FIZZBUZZ_HPP_
+#define FIZZBUZZ_HPP_
+
+#include <sstream>
+#include <string>
+
+std::string fizzbuzz(int const n) noexcept {
+    std::ostringstream buffer;
+    for (int i{1}; i <= n; ++i) {
+        bool f{true};
+
+        if (i % 3 == 0) {
+            buffer << "Fizz";
+            f = false;
+        }
+
+        if (i % 5 == 0) {
+            buffer << "Buzz";
+            continue;
+        }
+
+        if (f) {
+            buffer << i;
+        }
+    }
+
+    return buffer.str();
+}
+
+#endif // FIZZBUZZ_HPP_

src/lc-lru-cache/main.cpp → src/lc-lru-cache.hpp

@@ -2,6 +2,9 @@
 /// https://simontoth.substack.com/p/daily-bite-of-c-lru-cache
 /// https://leetcode.com/problems/lru-cache/
 
+#ifndef LC_LRU_CACHE_HPP_
+#define LC_LRU_CACHE_HPP_
+
 #include <cassert>
 #include <cstdint>
 #include <iterator>
@@ -175,131 +178,4 @@ class LRUCache final : public LRUCacheBase {
 
 } // namespace forfun::lrucache
 
-template <typename T>
-std::enable_if_t<std::is_base_of_v<forfun::lrucache::LRUCacheBase, T>, void>
-test() {
-    int volatile val{};
-
-    {
-        T cache{2};
-
-        cache.put(1, 1); // Cache is {{1, 1}}.
-
-        cache.put(2, 2); // Cache is {{1, 1, {2, 2}}.
-
-        val = cache.get(1);
-        assert(val == 1);
-
-        cache.put(
-            3, 3); // LRU key was 2. Evicts key 2. Cache is {{1, 1}, {3, 3}}.
-
-        val = cache.get(2); // Returns -1 (key not found).
-        assert(val == -1);
-
-        cache.put(
-            4, 4); // LRU key was 1; evicts key 1, cache is {{4, 4}, {3, 3}}.
-
-        val = cache.get(1);
-        assert(val == -1); // Returns -1 (key not found).
-
-        val = cache.get(3);
-        assert(val == 3);
-
-        val = cache.get(4);
-        assert(val == 4);
-    }
-
-    {
-        T cache(2);
-
-        cache.put(1, 1);
-
-        val = cache.get(1);
-        assert(val == 1);
-
-        cache.put(2, 2);
-
-        val = cache.get(2);
-        assert(val == 2);
-
-        cache.put(3, 3); // Evicts key 1.
-
-        val = cache.get(1);
-        assert(val == -1);
-
-        cache.put(2, 4);
-
-        val = cache.get(2);
-        assert(val == 4);
-
-        cache.put(4, 4); // Evicts key 3.
-
-        val = cache.get(3);
-        assert(val == -1);
-
-        val = cache.get(5);
-        assert(val == -1);
-    }
-
-    {
-        T cache(1);
-
-        cache.put(1, 1);
-
-        val = cache.get(1);
-        assert(val == 1);
-
-        cache.put(2, 2); // Evicts key 1.
-
-        val = cache.get(1);
-        assert(val == -1);
-
-        val = cache.get(2);
-        assert(val == 2);
-
-        cache.put(2, 3);
-
-        val = cache.get(2);
-        assert(val == 3);
-    }
-
-    {
-        T cache(3);
-
-        cache.put(1, 1);
-        cache.put(2, 2);
-        cache.put(3, 3);
-
-        val = cache.get(1);
-        assert(val == 1);
-
-        val = cache.get(2);
-        assert(val == 2);
-
-        val = cache.get(3);
-        assert(val == 3);
-
-        cache.put(4, 4); // Evicts key 1.
-
-        val = cache.get(1);
-        assert(val == -1);
-
-        val = cache.get(4);
-        assert(val == 4);
-
-        val = cache.get(2);
-        assert(val == 2);
-
-        cache.put(5, 5); // Evicts key 3, as key 2 was accessed recently.
-
-        val = cache.get(3);
-        assert(val == -1);
-    }
-}
-
-int main() {
-    test<forfun::lrucache::solution1::LRUCache>();
-    test<forfun::lrucache::solution1::LRUCache>();
-
-    return 0;
-}
+#endif // LC_LRU_CACHE_HPP_

src/palindrome.hpp

@@ -0,0 +1,36 @@
+// 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/Palindrome
+
+#ifndef PALINDROME_HPP_
+#define PALINDROME_HPP_
+
+#include <cctype>
+#include <concepts>
+#include <string>
+
+template <typename T = std::string, std::integral Tsize = typename T::size_type>
+[[nodiscard]] bool is_palindrome(T const& s) noexcept {
+    Tsize const len = (s.length()) / Tsize{2};
+    auto begin = s.cbegin();
+    auto end = --(s.cend());
+
+    for (Tsize i{0}; i < len; ++i) {
+        if (std::tolower(static_cast<unsigned char>(*begin))
+            != std::tolower(static_cast<unsigned char>(*end))) {
+            return false;
+        }
+
+        ++begin;
+        --end;
+    }
+
+    return true;
+}
+
+#endif // PALINDROME_HPP_

src/palindromic-number.hpp

@@ -0,0 +1,31 @@
+// 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/Palindromic_number
+
+#ifndef PALINDROMIC_NUMBER_HPP_
+#define PALINDROMIC_NUMBER_HPP_
+
+#include <cstdlib>
+
+[[nodiscard]] bool is_palindrome(int const n) noexcept {
+    if (n < 0) {
+        return false;
+    }
+
+    int nn{0};
+    std::div_t d{.quot = n, .rem = 0};
+    while (d.quot > 0) {
+        nn *= 10;
+        d = std::div(d.quot, 10);
+        nn += d.rem;
+    }
+
+    return n == nn;
+}
+
+#endif // PALINDROMIC_NUMBER_HPP_

src/project-euler/p0001-multiples-of-3-or-5/main.cpp → src/project-euler/p0001-multiples-of-3-or-5.hpp

@@ -13,8 +13,10 @@
 ///
 /// Find the sum of all the multiples of 3 or 5 below 1000.
 
+#ifndef PROJECT_EULER_P0001_MULTIPLES_OF_3_OR_5_HPP_
+#define PROJECT_EULER_P0001_MULTIPLES_OF_3_OR_5_HPP_
+
 #include <algorithm>
-#include <cassert>
 
 namespace {
 [[nodiscard]] inline constexpr int sum_2x(int const n, int const q) noexcept {
@@ -30,36 +32,4 @@ namespace {
     return (sum_2x(n, 3) + sum_2x(n, 5) - sum_2x(n, 15)) / 2;
 }
 
-int main() {
-    {
-        int const s{find_sum_mult_three_five(1)};
-        assert(s == 0);
-    }
-
-    {
-        int const s{find_sum_mult_three_five(4)};
-        assert(s == 3);
-    }
-
-    {
-        int s{find_sum_mult_three_five(6)};
-        assert(s == 8);
-    }
-
-    {
-        int const s{find_sum_mult_three_five(10)};
-        assert(s == 23);
-    }
-
-    {
-        int const s{find_sum_mult_three_five(11)};
-        assert(s == 33);
-    }
-
-    {
-        int s{find_sum_mult_three_five(1000)};
-        assert(s == 233168);
-    }
-
-    return 0;
-}
+#endif // PROJECT_EULER_P0001_MULTIPLES_OF_3_OR_5_HPP_