Fraser fir tree species. Growing and harvesting this species for Christmas trees and boughs is a multimillion-dollar business in the southern Appalachians. North Carolina produces the majority of Fraser fir Christmas trees. It requires from 7 to 10 years in the field to produce a high tree. In 2005, the North Carolina General Assembly passed legislation making the Fraser fir the official Christmas tree of North Carolina. Fraser fir The Fraser fir ("Abies fraseri") is a species of fir native to the Appalachian Mountains of the Southeastern United States. "Abies fraseri" is closely related to balsam fir ("Abies balsamea"), of which it
WAVL tree red–black tree, because they would in effect cause the recoloring of large subtrees of the red–black tree rather than making color changes only on a single path in the tree. This allows WAVL trees to perform fewer tree rotations per deletion, in the worst case, than red-black trees. WAVL tree In computer science, a WAVL tree or weak AVL tree is a self-balancing binary search tree. WAVL trees are named after AVL trees, another type of balanced search tree, and are closely related both to AVL trees and red–black trees, which all fall into a common framework of rank balanced