ツリー内の2つのノードの回転

struct TreeNode { //... PTreeNode& Child (Direction dir) { return dir == left? leftChild : rightChild; } }; class BST { private: 　　// ... 　　void Routate (PTreeNode, Direction); public: 　　// ... 　　void LeftRoutate (PTreeNode); void RightRoutate (PTreeNode); } void BST::Routate (PTreeNode node, Direction dir) { auto childDir = dir == TreeNode::left 　　　　　　　　　　? TreeNode::right 　　　　　　　　　　: TreeNode::left; auto child = node->Child (childDir); node->Child (childDir) = child->Child (dir); child->Child (dir)->parent = node; TransferParent (node, child); child->Child (dir) = node; node->parent = child; } void BST::LeftRoutate (PTreeNode node) { Routate (node, TreeNode::left); } void BST::RightRoutate (PTreeNode node) { Routate (node, TreeNode::right); }