4.3

4.3/iterate_max.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+#include <memory>
+#include <limits>
+
+template <typename T>
+struct Node
+{
+    T value;
+    std::unique_ptr<Node<T>> next;
+};
+
+template <typename T>
+T max(const std::unique_ptr<Node<T>>& node, T max_value)
+{
+    return (node)
+         ?  max(node->next, (node->value > max_value)
+                          ?  node->value
+                          :  max_value)
+         :  max_value;
+}
+
+int main()
+{
+    {
+        using NodeT = Node<std::string>;
+
+        auto head = std::make_unique<NodeT>(NodeT{"5", nullptr});
+        head->next = std::make_unique<NodeT>(NodeT{"12", nullptr});
+        head->next->next = std::make_unique<NodeT>(NodeT{"35", nullptr});
+        head->next->next->next = std::make_unique<NodeT>(NodeT{"JKFHDJKSFHKJSDJFSDKH", nullptr});
+
+        std::cout << "Size 1: " << max(head, std::string{}) << '\n';
+    }
+
+    {
+        using NodeT = Node<int>;
+
+        auto head = std::make_unique<NodeT>(NodeT{1, nullptr});
+        head->next = std::make_unique<NodeT>(NodeT{34, nullptr});
+        head->next->next = std::make_unique<NodeT>(NodeT{12, nullptr});
+        head->next->next->next = std::make_unique<NodeT>(NodeT{-4534, nullptr});
+        head->next->next->next->next = std::make_unique<NodeT>(NodeT{std::numeric_limits<int>::max(), nullptr});
+
+        std::cout << "Size 2: " << max(head, std::numeric_limits<int>::min()) << '\n';
+    }
+
+    {
+        using NodeT = Node<char>;
+
+        auto head = std::make_unique<NodeT>(NodeT{'#', nullptr});
+
+        std::cout << "Size 3: " << max(head, std::numeric_limits<char>::min()) << '\n';
+    }
+
+    {
+        std::cout << "Size empty: " << max(std::unique_ptr<Node<double>>(), std::numeric_limits<double>::min()) << '\n';
+    }
+}