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Fix the return type of binary search tree and avl tree

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krahets
2023-04-14 05:47:20 +08:00
parent 9c9c8b7574
commit f7ae9c8a02
24 changed files with 247 additions and 451 deletions
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44
codes/c/chapter_tree/binary_search_tree.c
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@@ -69,15 +69,16 @@ TreeNode *search(binarySearchTree *bst, int num) {
}
/* 插入节点 */
TreeNode *insert(binarySearchTree *bst, int num) {
void insert(binarySearchTree *bst, int num) {
// 若树为空，直接提前返回
if (bst->root == NULL) return NULL;
if (bst->root == NULL)
return;
TreeNode *cur = bst->root, *pre = NULL;
// 循环查找，越过叶节点后跳出
while (cur != NULL) {
// 找到重复节点，直接返回
if (cur->val == num) {
return NULL;
return;
}
pre = cur;
if (cur->val < num) {
@@ -95,24 +96,14 @@ TreeNode *insert(binarySearchTree *bst, int num) {
} else {
pre->left = node;
}
return node;
}
/* 获取中序遍历中的下一个节点（仅适用于 root 有左子节点的情况） */
TreeNode *getInOrderNext(TreeNode *root) {
if (root == NULL) return root;
// 循环访问左子节点，直到叶节点时为最小节点，跳出
while (root->left != NULL) {
root = root->left;
}
return root;
}
/* 删除节点 */
// 由于引入了 stdio.h ，此处无法使用 remove 关键词
TreeNode *removeNode(binarySearchTree *bst, int num) {
void removeNode(binarySearchTree *bst, int num) {
// 若树为空，直接提前返回
if (bst->root == NULL) return NULL;
if (bst->root == NULL)
return;
TreeNode *cur = bst->root, *pre = NULL;
// 循环查找，越过叶节点后跳出
while (cur != NULL) {
@@ -128,9 +119,8 @@ TreeNode *removeNode(binarySearchTree *bst, int num) {
}
}
// 若无待删除节点，则直接返回
if (cur == NULL) {
return NULL;
}
if (cur == NULL)
return;
// 判断待删除节点是否存在子节点
if (cur->left == NULL || cur->right == NULL) {
/* 子节点数量 = 0 or 1 */
@@ -145,14 +135,16 @@ TreeNode *removeNode(binarySearchTree *bst, int num) {
} else {
/* 子节点数量 = 2 */
// 获取中序遍历中 cur 的下一个节点
TreeNode *nex = getInOrderNext(cur->right);
int tmp = nex->val;
// 递归删除节点 nex
removeNode(bst, nex->val);
// 将 nex 的值复制给 cur
cur->val = tmp;
TreeNode *tmp = cur->right;
while (tmp->left != NULL) {
tmp = tmp->left;
}
int tmpVal = tmp->val;
// 递归删除节点 tmp
removeNode(bst, tmp->val);
// 用 tmp 覆盖 cur
cur->val = tmpVal;
}
return cur;
}
/* Driver Code */