AVL树节点声明：
1 struct AvlNode 2 { 3 Comparable element; 4 AvlNode *left; 5 AvlNode *right; 6 int height; 7 8 AvlNode( const Comparable & theElement,AvlNode *lt,AvlNode *rt,int h=0):element ( theElement),left(lt),right(rt),height(t) 9 };
计算节点高度：
1 int height( AvlNode * t) const 2 { 3 return t == NULL ? -1 : t->height; 4 }
向AVL中插入操作：
void insert( const Comparable & x,AvlNode * & t) { if(t == NULL) t = new AvlNode ( x,NULL,NULL); else if (x < t->element); { insert( x ,t->left); if(height(t->left)-height(t->right) == 2) if(x < t->element) rotateWithLeftChild(t); else doubleWithLeftChild(t); } else if (t->element < x) { insert(x,t->right); if(height(t->right) - height(t->left) == 2) if(t->right->element < x) rotateWithLeftChild(t); else doubleWithLeftChild(t); } else ; t->height = max(height(t->left),height(t->right))+1; }
执行单旋转过程：
1 void rotateWithLeftChild(AvlNode * & k2) 2 { 3 AvlNode *k1 = k2->left; 4 k2->left = k1->right; 5 k1->right = k2; 6 k2->height = max(height(k2->left),height(k2->right))+1; 7 k1->height = max(height(k1->left),height(k1->right))+1; 8 k2=k1; 9 }
执行双旋转过程：
void doubleWithLeftChild( AvlNode * & k3) { rotateWithLeftChild(k3->left); rotateWithLeftChild(k3); }