Pseudocode for Red-Black Trees

enum COLOR { rbRED, rbBLACK };
struct RBNode
{
  RBNode *left;
  RBNode *right;
  RBNode *parent;
  COLOR color;
  void *item;
};


RBInsert(Root node of RBTree, Item to insert)
{
  RBNode *X = node, *Y;
  Insert new node into RBTree in usual manner (it's a BST)
  Set new node's color to RED and call it X

    // The Red/Black property may have been destroyed
    // so we have to restore it
  while (X is not the Root) and (X's Parent is RED)
  {
    if (X's Parent is a LEFT child)
    {
        // If X's Parent is a LEFT, Uncle must be a RIGHT
      Set Y to X's Uncle (Uncle is Grandparent's RIGHT child)
      if (Y is RED)
      {
          // Case #1, Change the tri-node's colors
        Set X's Parent's color to BLACK
        Set Y's color to BLACK
        Set X's Grandparent's color to RED
        Set X to Grandparent
      }
      else // Y is BLACK
      {
          // and X is RIGHT, Case #2
          // move X up and rotate it (rotates child into Parent's spot)
        if (X is a RIGHT child)
        {
          Set X to Parent
          Rotate LEFT about new X 
        }
        
          // Case #3
        Set X's Parent's color to BLACK
        Set X's Grandparent's color to RED
        Rotate RIGHT about X's Grandparent;
      }
    }
    else // X's Parent is a RIGHT child (symmetrical to above code)
    {
        // If X's Parent is a RIGHT, Uncle must be a LEFT
      Set Y to X's Uncle (Uncle is Grandparent's LEFT child)
      if (Y is RED)
      {
          // Case #1, Change the tri-node's colors
        Set X's Parent's color to BLACK
        Set Y's color to BLACK
        Set X's Grandparent's color to RED
        Set X to Grandparent
      }
      else
      {
          // and X is LEFT, Case #2
          // move X up and rotate it (rotates child into Parent's spot)
        if (X is a LEFT child)
        {
          Set X to Parent
          Rotate RIGHT about new X 
        }
        
          // Case #3
        Set X's Parent's color to BLACK
        Set X's Grandparent's color to RED
        Rotate LEFT about X's Grandparent;
      }
    }
  }
}