chore: import upstream snapshot with attribution

data_structures/stack_using_array.cpp

@@ -0,0 +1,179 @@
+#include <cassert>    /// For std::assert
+#include <iostream>   /// For std::cout
+#include <memory>     /// For std::unique_ptr
+#include <stdexcept>  /// For std::out_of_range
+
+/**
+ * @namespace
+ * @brief data_structures
+ */
+namespace data_structures {
+/**
+ * @brief Class representation of a stack
+ * @tparam T The type of the elements in the stack
+ */
+template <typename T>
+class Stack {
+ private:
+    std::unique_ptr<T[]> stack;  ///< Smart pointer to the stack array
+    int stackSize;               ///< Maximum size of the stack
+    int stackIndex;  ///< Index pointing to the top element of the stack
+
+ public:
+    /**
+     * @brief Constructs a new Stack object
+     *
+     * @param size Maximum size of the stack
+     */
+    Stack(int size) : stack(new T[size]), stackSize(size), stackIndex(-1) {}
+
+    /**
+     * @brief Checks if the stack is full
+     *
+     * @return true if the stack is full, false otherwise
+     */
+    bool full() const { return stackIndex == stackSize - 1; }
+
+    /**
+     * @brief Checks if the stack is empty
+     * @return true if the stack is empty, false otherwise
+     */
+    bool empty() const { return stackIndex == -1; }
+
+    /**
+     * @brief Pushes an element onto the stack
+     *
+     * @param element Element to push onto the stack
+     */
+    void push(T element) {
+        if (full()) {
+            throw std::out_of_range("Stack overflow");
+        } else {
+            stack[++stackIndex] = element;
+        }
+    }
+
+    /**
+     * @brief Pops an element from the stack
+     *
+     * @return The popped element
+     * @throws std::out_of_range if the stack is empty
+     */
+    T pop() {
+        if (empty()) {
+            throw std::out_of_range("Stack underflow");
+        }
+        return stack[stackIndex--];
+    }
+
+    /**
+     * @brief Displays all elements in the stack
+     */
+    void show() const {
+        for (int i = 0; i <= stackIndex; i++) {
+            std::cout << stack[i] << "\n";
+        }
+    }
+
+    /**
+     * @brief Displays the topmost element of the stack
+     *
+     * @return The topmost element of the stack
+     * @throws std::out_of_range if the stack is empty
+     */
+    T topmost() const {
+        if (empty()) {
+            throw std::out_of_range("Stack underflow");
+        }
+        return stack[stackIndex];
+    }
+
+    /**
+     * @brief Displays the bottom element of the stack
+     *
+     * @return The bottom element of the stack
+     * @throws std::out_of_range if the stack is empty
+     */
+    T bottom() const {
+        if (empty()) {
+            throw std::out_of_range("Stack underflow");
+        }
+        return stack[0];
+    }
+};
+}  // namespace data_structures
+
+/**
+ * @brief Self-test implementations
+ * @returns void
+ */
+static void test() {
+    data_structures::Stack<int> stack(5);
+
+    // Test empty and full operations
+    assert(stack.empty());
+    assert(!stack.full());
+
+    // Test pushing elements and checking topmost
+    stack.push(10);
+    assert(stack.topmost() == 10);
+
+    stack.push(20);
+    assert(stack.topmost() == 20);
+
+    stack.push(30);
+    stack.push(40);
+    stack.push(50);
+    assert(stack.full());
+
+    // Test stack overflow
+    try {
+        stack.push(60);
+    } catch (const std::out_of_range& e) {
+        assert(std::string(e.what()) == "Stack overflow");
+    }
+
+    // Test popping elements
+    assert(stack.pop() == 50);
+    assert(stack.pop() == 40);
+    assert(stack.pop() == 30);
+
+    // Check topmost and bottom elements
+    assert(stack.topmost() == 20);
+    assert(stack.bottom() == 10);
+
+    assert(stack.pop() == 20);
+    assert(stack.pop() == 10);
+
+    assert(stack.empty());
+    assert(!stack.full());
+
+    // Test stack underflow
+    try {
+        stack.pop();
+    } catch (const std::out_of_range& e) {
+        assert(std::string(e.what()) == "Stack underflow");
+    }
+
+    try {
+        stack.topmost();
+    } catch (const std::out_of_range& e) {
+        assert(std::string(e.what()) == "Stack underflow");
+    }
+
+    try {
+        stack.bottom();
+    } catch (const std::out_of_range& e) {
+        assert(std::string(e.what()) == "Stack underflow");
+    }
+}
+
+/**
+ * @brief Main function
+ * @returns 0 on exit
+ */
+int main() {
+    test();  // run self-test implementations
+    std::cout << "All tests passed!" << std::endl;
+    return 0;
+}