伸展树实现文件C语言(Aplaytree.c)

  学树第四天,第一课伸展树.写了8小时,好困啊.感觉真好.写完自己又读了一遍,记下了.

  贴出来,还希望有人愿意跟我交流.

/* splay_tree.c -- 伸展树实现文件 */ #include <stdio.h> #include <stdlib.h> #include "splay_tree.h" /* 局部数据类型定义 */ typedef Position Stack_Item ; typedef struct stack_node { Stack_Item item ; struct stack_node * next ; } Stack_Node ; typedef Stack_Node * Stack ; /* 局部函数声明 */ Position Make_Node (const Item item) ; int Left_Is_Greater_Than_Right (const Item left, const Item right) ; int Left_Is_Lesser_Than_Right (const Item left, const Item right) ; void Copy_Item_To_Node (const Item * const pitem, Position * const pnew_node) ; Position Discover_Item (const SplayTree tree, const Item item) ; Position The_Parent_Of (const SplayTree tree, const Position target) ; Position Single_Rotate_With_Left (Position K2) ; Position Single_Rotate_With_Right (Position K2) ; Position Zig_Zig_Rotate_With_Left (Position K3) ; Position Zig_Zig_Rotate_With_Right (Position K3) ; Position Zig_Zag_Rotate_With_Left (Position K3) ; Position Zig_Zag_Rotate_With_Right (Position K3) ; void Initialize_Stack (Stack * pstack) ; int Stack_Is_Empty (const Stack * const pstack) ; int Stack_Is_Full (void) ; int Push (Stack * pstack, const Stack_Item item) ; Stack_Item Top (const Stack * const pstack, const int number) ; int Stack_Item_Count (const Stack * const pstack) ; int Pop (Stack * pstack, const int number) ; void Empty_The_Stack (Stack * pstack) ; Stack Discover_Item_By_Use_Stack (const SplayTree tree, const Item item) ; /* 接口函数定义 */ void IintializeSplayTree (SplayTree * ptree) { (*ptree) = NULL ; } int SplayTreeIsEmpty (const SplayTree tree) { return NULL == tree ; } int SplayTreeIsFull (void) { Position temp ; temp = (Node *) malloc (sizeof (Node)) ; if (NULL == temp) return 1 ; else { free (temp) ; return 0 ; } } SplayTree AddItem (SplayTree tree, const Item item) { Position new_node, scan = tree ; new_node = Make_Node (item) ; if (NULL == new_node) return tree ; if (SplayTreeIsEmpty (tree)) return tree = new_node ; while (scan != NULL) { if (Left_Is_Greater_Than_Right (item, scan -> item)) { if (NULL == scan -> right) break ; else scan = scan -> right ; } else if (Left_Is_Lesser_Than_Right (item, scan -> item)) { if (NULL == scan -> left) break ; else scan = scan -> left ; } /* 发生需要重复添加的情况 */ else return tree ; } if (Left_Is_Greater_Than_Right (item, scan -> item)) scan -> right = new_node ; else if (Left_Is_Lesser_Than_Right (item, scan -> item)) scan -> left = new_node ; return tree ; } SplayTree Insert (SplayTree tree, const Item item) { Position new_node ; if (NULL == tree) { new_node = Make_Node (item) ; return new_node ; } if (Left_Is_Greater_Than_Right (item, tree -> item)) tree -> right = Insert (tree -> right, item) ; else if (Left_Is_Lesser_Than_Right (item, tree -> item)) tree -> left = Insert (tree -> left, item) ; /* 发生需要重复添加的情况 */ else return tree ; return tree ; } Position FindMax (const SplayTree tree) { Position scan = tree ; if (NULL == scan) return NULL ; while (scan -> right != NULL) scan = scan -> right ; return scan ; } Position FindMin (const SplayTree tree) { Position scan = tree ; if (NULL == scan) return NULL ; while (scan -> left != NULL) scan = scan -> left ; return scan ; } SplayTree Find (SplayTree tree, const Item item) { Position target, parent, grandfather, greatgrandfather ; target = Discover_Item (tree, item) ; /* 如果未找到 */ if (NULL == target) return tree ; /* 循环条件:当前结点不是根节点 */ while ((parent = The_Parent_Of (tree, target)) != NULL) { /* 如果父节点是根节点 */ if (tree == parent) { if (Left_Is_Greater_Than_Right (item, parent -> item)) target = Single_Rotate_With_Right (parent) ; else target = Single_Rotate_With_Left (parent) ; } else { grandfather = The_Parent_Of (tree, parent) ; /* 如果在父结点左侧 */ if (Left_Is_Lesser_Than_Right (target -> item, parent -> item)) { if (Left_Is_Greater_Than_Right (parent -> item, grandfather -> item)) target = Zig_Zag_Rotate_With_Right (grandfather) ; /* 右之字形旋转 */ else target = Zig_Zig_Rotate_With_Left (grandfather) ; /* 左一字形旋转 */ } /* 如果在父结点右侧 */ else { if (Left_Is_Greater_Than_Right (parent -> item, grandfather -> item)) target = Zig_Zig_Rotate_With_Right (grandfather) ; /* 右一字形旋转 */ else target = Zig_Zag_Rotate_With_Left (grandfather) ; /* 左之字形旋转 */ } /* 如果爷结点之上才是根节点 */ if (grandfather != tree) { greatgrandfather = The_Parent_Of (tree, grandfather) ; if (Left_Is_Greater_Than_Right (grandfather -> item, greatgrandfather -> item)) greatgrandfather -> right = target ; else greatgrandfather -> left = target ; /* 更新循环条件.即目标结点在树中位置 */ target = Discover_Item (tree, item) ; } } } return target ; } SplayTree Find_By_Use_Stack (SplayTree tree, const Item item) { Stack stack ; Position target, parent, grandfather, greatgrandfather ; target = Discover_Item (tree, item) ; if (NULL == target) return tree ; stack = Discover_Item_By_Use_Stack (tree, item) ; while (!Stack_Is_Empty (&stack)) { parent = Top (&stack, 1) ; /* 如果父结点是根节点(即栈中只有一个结点) */ if (1 == Stack_Item_Count (&stack)) { if (Left_Is_Greater_Than_Right (item, parent -> item)) target = Single_Rotate_With_Right (parent) ; else target = Single_Rotate_With_Left (parent) ; Pop (&stack, 1) ; } else { grandfather = Top (&stack, 2) ; /* 如果在父结点左侧 */ if (Left_Is_Lesser_Than_Right (target -> item, parent -> item)) { if (Left_Is_Greater_Than_Right (parent -> item, grandfather -> item)) target = Zig_Zag_Rotate_With_Right (grandfather) ; /* 右之字形旋转 */ else target = Zig_Zig_Rotate_With_Left (grandfather) ; /* 左一字形旋转 */ } /* 如果在父结点右侧 */ else { if (Left_Is_Greater_Than_Right (parent -> item, grandfather -> item)) target = Zig_Zig_Rotate_With_Right (grandfather) ; /* 右一字形旋转 */ else target = Zig_Zag_Rotate_With_Left (grandfather) ; /* 左之字形旋转 */ } if (Stack_Item_Count (&stack) > 2) { greatgrandfather = Top (&stack, 3) ; if (Left_Is_Greater_Than_Right (grandfather -> item, greatgrandfather -> item)) greatgrandfather -> right = target ; else greatgrandfather -> left = target ; } Pop (&stack, 2) ; } } return target ; } SplayTree Delete (SplayTree tree, const Item item) { SplayTree left_subtree, right_subtree ; Position new_root, temp ; /* 如果未找到 */ if (NULL == Discover_Item (tree, item)) return tree ; tree = Find_By_Use_Stack (tree, item) ; left_subtree = tree -> left ; right_subtree = tree -> right ; temp = tree ; if (NULL == left_subtree && NULL == right_subtree) tree = NULL ; /* 如果左子树为空,右子树不为空 */ else if (NULL == tree -> left) { new_root = FindMin (right_subtree) ; tree = Find_By_Use_Stack (right_subtree, new_root -> item) ; } /* 否则左子树不为空,则当前正在处理理想情况.右子树是否为空无关紧要 */ else { new_root = FindMax (left_subtree) ; left_subtree = Find_By_Use_Stack (left_subtree, new_root -> item) ; /* 左子树中最大数据的结点被旋转到根结点的位置,它一定没有右子树 */ left_subtree -> right = right_subtree ; tree = left_subtree ; } free (temp) ; return tree ; } void InorderTraversal (const SplayTree tree, void (* pfun) (const Item item)) { if (tree != NULL) { InorderTraversal (tree -> left, pfun) ; (*pfun) (tree -> item) ; InorderTraversal (tree -> right, pfun) ; } } /* 局部函数定义 */ Position Make_Node (const Item item) { Position new_node ; new_node = (Node *) malloc (sizeof (Node)) ; if (NULL == new_node) return NULL ; else { Copy_Item_To_Node (&item, &new_node) ; new_node -> left = NULL ; new_node -> right = NULL ; return new_node ; } } int Left_Is_Greater_Than_Right (const Item left, const Item right) { return left > right ; } int Left_Is_Lesser_Than_Right (const Item left, const Item right) { return left < right ; } void Copy_Item_To_Node (const Item * const pitem, Position * const pnew_node) { (*pnew_node) -> item = *pitem ; } Position Discover_Item (const SplayTree tree, const Item item) { Position scan = tree ; while (scan != NULL) { if (Left_Is_Greater_Than_Right (item, scan -> item)) scan = scan -> right ; else if (Left_Is_Lesser_Than_Right (item, scan -> item)) scan = scan -> left ; /* 接下来找到了,返回该结点的指针 */ else return scan ; } return NULL ; } Position The_Parent_Of (const SplayTree tree, const Position target) { Position parent = tree, scan = tree ; if (tree == target) return NULL ; while (scan != NULL) { if (Left_Is_Greater_Than_Right (target -> item, scan -> item)) { parent = scan ; scan = scan -> right ; } else if (Left_Is_Lesser_Than_Right (target -> item, scan -> item)) { parent = scan ; scan = scan -> left ; } else return parent ; } return NULL ; } Position Single_Rotate_With_Left (Position K2) { Position K1 = K2 -> left ; K2 -> left = K1 -> right ; K1 -> right = K2 ; return K1 ; } Position Single_Rotate_With_Right (Position K2) { Position K1 = K2 -> right ; K2 -> right = K1 -> left ; K1 -> left = K2 ; return K1 ; } /* 一字型旋转是从K3 - K2 - K1 */ Position Zig_Zig_Rotate_With_Left (Position K3) { Position K2 = K3 -> left ; Position K1 = K2 -> left ; K3 -> left = K2 -> right ; K2 -> right = K3 ; K2 -> left = K1 -> right ; K1 -> right = K2 ; return K1 ; } Position Zig_Zig_Rotate_With_Right (Position K3) { Position K2 = K3 -> right ; Position K1 = K2 -> right ; K3 -> right = K2 -> left ; K2 -> left = K3 ; K2 -> right = K1 -> left ; K1 -> left = K2 ; return K1 ; } /* 之字形旋转是从K1 - K2 - K3 */ Position Zig_Zag_Rotate_With_Left (Position K3) { Position K2 = K3 -> left ; Position K1 = K2 -> right ; K2 -> right = K1 -> left ; K1 -> left = K2 ; K3 -> left = K1 -> right ; K1 -> right = K3 ; return K1 ; } Position Zig_Zag_Rotate_With_Right (Position K3) { Position K2 = K3 -> right ; Position K1 = K2 -> left ; K2 -> left = K1 -> right ; K1 -> right = K2 ; K3 -> right = K1 -> left ; K1 -> left = K3 ; return K1 ; } /* 栈部分函数定义 */ void Initialize_Stack (Stack * pstack) { *pstack = NULL ; } int Stack_Is_Empty (const Stack * const pstack) { return NULL == *pstack ; } int Stack_Is_Full (void) { Stack_Node * temp ; temp = (Stack_Node *) malloc (sizeof (Stack_Node)) ; if (NULL == temp) return 1 ; else { free (temp) ; return 0 ; } } int Push (Stack * pstack, const Stack_Item item) { Stack_Node * new_node ; new_node = (Stack_Node *) malloc (sizeof (Stack_Node)) ; if (NULL == new_node) return 0 ; new_node -> item = item ; if (Stack_Is_Empty (pstack)) { new_node -> next = NULL ; *pstack = new_node ; } else { new_node -> next = *pstack ; *pstack = new_node ; } return 1 ; } Stack_Item Top (const Stack * const pstack, const int number) { Stack_Node * scan = *pstack ; int count = 1 ; while (count < number) { if (NULL == scan) return NULL ; scan = scan -> next ; /* Don't forgrt this line!!! */ count++ ; } return scan -> item ; } int Stack_Item_Count (const Stack * const pstack) { Stack_Node * temp = *pstack ; int count = 0 ; while (temp != NULL) { temp = temp -> next ; /* Don't forget this line!!! */ count++ ; } return count ; } int Pop (Stack * pstack, const int number) { Stack_Node * temp ; int count = 0 ; while (count < number) { if (NULL == *pstack) return 0 ; temp = *pstack ; *pstack = (*pstack) -> next ; free (temp) ; /* Don't forget this line!!! */ count++ ; } return 1 ; } void Empty_The_Stack (Stack * pstack) { Stack_Node * temp ; while (*pstack != NULL) { temp = *pstack ; *pstack = (*pstack) -> next ; free (temp) ; } } Stack Discover_Item_By_Use_Stack (const SplayTree tree, const Item item) { Stack stack ; Position scan = tree ; Initialize_Stack (&stack) ; while (scan != NULL) { Push (&stack, scan) ; if (Left_Is_Greater_Than_Right (item, scan -> item)) scan = scan -> right ; else if (Left_Is_Lesser_Than_Right (item, scan -> item)) scan = scan -> left ; else { /* 弹出目标找到的结点 */ Pop (&stack, 1) ; return stack ; } } Empty_The_Stack (&stack) ; return NULL ; }