[Javase] Data structure (basic concept of AVL tree)

The AVL tree is a highly balanced two-fork tree, with a height difference of two subtrees of any node <=1

Implementing the AVL Tree

Defines an AVL tree,avltree, that defines Avltree 's intra-node class Avlnode, The node contains the following attributes:

1.key-- keywords to sort the nodes of the AVL Tree

2.left--left dial hand tree

3.right--Right sub-tree

4.height--Height

If you insert a node in the AVL tree, it may cause the AVL tree to lose its balance in four different states:

LL: Zo,leftleft

LR: Around,leftright

RL: Right-left,rightleft

RR: Right, right,RightRight

Solve the above situation

Solve LL, need left single rotation

Resolve RR, need right single rotation

To resolve LR, you need to first right single rotation, then left single rotation

To solve RL, you need to turn the left single rotation, then the right single rotation

Achieve left single rotation

K1,K2

K2 left to K1 .

K1 right to the left of K2

K2 to K1 right .

Achieve right single rotation

K1,K2

K1 right to K2 .

K2 left to K1 right .

K1 to K2 's left.

The height of the node is its left subtree or right subtree, and the height of the tall one adds 1 .

/*** AVL Tree Test *@authorTaoshihan *@param<T> **/ Public classAvltree<textendsComparable<t>> {    PrivateAvlnode Mroot;//root node    classAvlnode<textendsComparable<t>>{        PrivateT key;//Key Value        Private intHeight//Height        PrivateAvlnode left;//left dial hand tree        PrivateAvlnode right;//Right sub-tree         PublicAvlnode (T key,avlnode Left,avlnode right) { This. key=key;  This. left=Left ;  This. right=Right ;  This. height=0; }    }    /*** Get node Height *@paramTree *@return     */     Public intHeight (avlnode<t>tree) {        if(tree!=NULL){            returnTree.height; }        return0; }    /*** Take out the tall one in the left and right subtree *@paramA *@paramb *@return     */     Public intMaxHeight (intAintb) {        returnA>b?a:b; }    /*** Left single rotation *@paramK2 *@return     */     PublicAvlnode<t> Leftleftrotation (avlnode<t>K2)        {Avlnode K1; K1=K2.left; K2.left=K1.right; K1.right=K2; K2.height=maxheight (height (k2.left), height (k2.right)); K1.height=maxheight (height (k1.left), height (k1.right)); returnK1; }    /*** Right Single rotation *@paramK2 *@return     */     PublicAvlnode<t> Rightrightrotation (avlnode<t>K1)        {Avlnode K2; K2=K1.right; K1.right=K2.left; K2.left=K1; K2.height=maxheight (height (k2.left), height (k2.right)); K1.height=maxheight (height (k1.left), height (k1.right)); returnK2; }

[Javase] Data structure (basic concept of AVL tree)