Hello, So, I'm trying to implement a traversal preorder binary search tree algorithm but I'm having trouble understanding what I have to do.

How do I implement this function?

struct BinaryTreeNode { int key; BinaryTreeNode* left = 0; BinaryTreeNode* right = 0; //Initialized to NULL //Initialized to NULL #define Binary_MAX_SIZE 100 * Defines a binary search tree traversal data structure struct BinaryTreeTraversal { int keys (Binary_MAX_SIZE] ; int size = 0; }; void traversePreorder (const BinaryTreeNode* tree, BinaryTreeTraversal& traversal) { //If the tree is not NULL, process the key of the 'tree'. //Continue, traverse preorder on the left sub-tree. //Continue, traverse preorder on the right sub-tree. if (tree != NULL) { traversePreorder (tree->left, traversal); traversePreorder (tree->right, traversal); } }