二叉排序树算法

结点的删除有点错误？？以后再改正

#include <stdio.h>#include <stdlib.h>#define ARRAYLEN 10int source[] = {54, 90, 6, 69, 12, 37, 92, 28, 65, 83};typedef struct bst{int data;struct bst *left;struct bst *right;}BSTree;//BinarySortTree//将一个数插入到二叉排序树中void InsertBST(BSTree *t, int key){BSTree *p, *parent, *head;p = (BSTree *)malloc(sizeof(BSTree *));if (!p){printf("error\n");exit(0);}p->data = key;p->left = NULL;p->right = NULL;head = t;while(head){parent = head;if (key < head->data)head = head->left;elsehead = head->right;}if (key < parent->data)parent->left = p;elseparent->right = p;}//创建一个二叉排序树void CreateBST(BSTree *t, int data[], int n){int i;t->data = data[0];t->left = t->right = NULL;for (i = 1; i < n; i++)InsertBST(t, data[i]);}//中序遍历void BST_LDR(BSTree *t){if (t){BST_LDR(t->left);printf("%d ", t->data);BST_LDR(t->right);}return;}//查找结点BSTree *SearchBST(BSTree *t, int key){if (!t || t->data == key)return t;else if (key > t->data)return (SearchBST(t->right, key));elsereturn (SearchBST(t->left, key));}//删除结点/*三种情况：1、若删除的结点是二叉排序树的叶结点，即t->left和t->right都为空。这时只需要修改t结点的父结点的指针，并释放t结点占用的内存即可。2、若t结点只有一个子树（即t->left或t->right为空），这时只需要修改t结点的父结点，使其子结点的值为t->left,t->right3、若t结点有两个子树（即t->left和t->right都不为空），这时，只需在被删除结点的右子树中查找，找到最左侧的叶结点，将该叶结点的值移到被删除结点即可。*/void BST_Delete(BSTree *t, int key){BSTree *p, *parent, *l, *ll;int child = 0;//0表示左子树，1表示右子树if (!t) return;p = t;while(p){if (p->data == key){if (!p->left && !p->right)//叶结点{if (p == t){free(p);}else if (child == 0){parent->left = NULL;free(p);}else{parent->right = NULL;free(p);}}else if (!p->left)//左子树为空，右子树不为空{if (child == 0)//是父结点的左子树parent->left = p->right;elseparent->right = p->left;free(p);}else//左右子树都不为空{ll = p;//保存左子树的父结点l = p->right;//从当前结点的右子树进行查找while (l->left){ll = l;l = l->left;//查找左子树}p->data = l->data;ll->left = NULL;free(l->right);//这里可能有问题?}p = NULL;}else if (key < p->data){child = 0;parent = p;p = p->left;}else{child = 1;parent = p;p = p->right;}}}int main(){int key, i;BSTree bst, *pos;printf("原来的数据为:\n");for (i = 0; i < ARRAYLEN; i++)printf("%d ", source[i]);CreateBST(&bst, source, ARRAYLEN);printf("\n遍历二叉排序树结果：\n");BST_LDR(&bst);printf("\n输入要查找的数值:");scanf("%d", &key);pos = SearchBST(&bst, key);if (pos)printf("查找成功，结点%d的地址为%x\n", pos->data, pos);elseprintf("查找失败！\n");//printf("输入要删除的结点:");//scanf("%d", &key);//BST_Delete(&bst, key);//printf("\n删除结点%d之后遍历二叉排序树结果：\n", key);//BST_LDR(&bst);getchar();getchar();return 0;}