style: resolve -Wreorder (#2950)

Co-authored-by: realstealthninja <68815218+realstealthninja@users.noreply.github.com>

data_structures/stack_using_array.cpp

@@ -25,7 +25,7 @@ class Stack {
      *
      * @param size Maximum size of the stack
      */
-    Stack(int size) : stackSize(size), stackIndex(-1), stack(new T[size]) {}
+    Stack(int size) : stack(new T[size]), stackSize(size), stackIndex(-1) {}
 
     /**
      * @brief Checks if the stack is full

data_structures/tree_234.cpp

@@ -39,9 +39,9 @@ class Node {
      * @param item the first value we insert to the node
      */
     explicit Node(int64_t item)
-        : count(1),
-          items({{item, 0, 0}}),
-          children({{nullptr, nullptr, nullptr, nullptr}}) {}
+        : items({{item, 0, 0}}),
+          children({{nullptr, nullptr, nullptr, nullptr}}),
+          count(1) {}
 
     /**
      * @brief Get the item count that current saved in the node