AVL树的节点声明
#ifndef _AvlTree_H
struct AvlNode;
typedef struct AvlNode *Position;
typedef struct AvlNode *AvlTree;
AvlTree MakeEmpty(AvlTree T);
Position Find( ElementType X,AvlTree T);
Position FindMin(AvlTree T);
Position FindMax(AvlTree T);
AvlTree Insert(ElementType X,AvlTree T);
AvlTree Delete(ElementType X,AvlTree T);
ElementType Retrieve(Position P);
#endif
struct AvlNode
{
ElementType Element;
AvlTree Left;
AvlTree Right;
int Height;
};
计算AVL节点高度
static int Height(Position P)
{
if(P == NULL)
return -1;
else
return P->Height;
}
向AVL树插入节点
AvlTree Insert(ElementType X,AvlTree T)
{
if(T == NULL)
{
T = malloc(sizeof(struct AvlNode));
if(T == NULL)
FataError("Out of space!!!");
else
{
T->Element = X;T->Height = 0;
T->Left = T->Right = NULL;
}
}
else if(X < T->Element)
{
T->Left = Insert(X,T->Left);
if(Height(T->Left)-Height(T->Right) == 2)
if(X < T->Left->Element)
T = SingleRotateWinthLeft(T);
else
T = DoubleRotateWithLeft(T);
}
else if (X > T->Element)
{
T->Right = Insert(X,T->Right);
if(Height(T->Right) - Height(T->Left) == 2)
if(X > T->Right->Element)
T = SingleRotateWinthRight(T);
else
T = DoubleRotateWithRight(T);
}
T->Height = Max(Height(T->Left),Height(T->Right)) + 1;
return T;
}
执行单旋转操作
static Position SingleRotateWinthLeft(Position K2)
{
Position K1;
K1 = k2->Left;
K2->Left = K1->Right;
k1->Right = K2;
K2->Height = Max(Height(K2->Left),Height(K2->Right)) + 1;
K1->Height = Max(Height(K1->Left),K2->Height)) + 1;
return K1;
}
执行双旋转操作
static Position DoubleRotateWithLeft(Position K3)
{
K3->Left = SingleRotateWithRight(K3->Left);
return SingleRotateWithLeft(K3);
}