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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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30
codes/java/chapter_tree/binary_search_tree.java
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@ -56,16 +56,16 @@ class BinarySearchTree {
}
/* 插入节点 */
public TreeNode insert(int num) {
public void insert(int num) {
// 若树为空，直接提前返回
if (root == null)
return null;
return;
TreeNode cur = 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;
// 插入位置在 cur 的右子树中
if (cur.val < num)
@ -80,14 +80,13 @@ class BinarySearchTree {
pre.right = node;
else
pre.left = node;
return node;
}
/* 删除节点 */
public TreeNode remove(int num) {
public void remove(int num) {
// 若树为空，直接提前返回
if (root == null)
return null;
return;
TreeNode cur = root, pre = null;
// 循环查找，越过叶节点后跳出
while (cur != null) {
@ -104,7 +103,7 @@ class BinarySearchTree {
}
// 若无待删除节点，则直接返回
if (cur == null)
return null;
return;
// 子节点数量 = 0 or 1
if (cur.left == null || cur.right == null) {
// 当子节点数量 = 0 / 1 时， child = null / 该子节点
@ -118,14 +117,15 @@ class BinarySearchTree {
// 子节点数量 = 2
else {
// 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
remove(nex.val);
// 将 nex 的值复制给 cur
cur.val = tmp;
TreeNode tmp = cur.right;
while (tmp.left != null) {
tmp = tmp.left;
}
// 递归删除节点 tmp
remove(tmp.val);
// 用 tmp 覆盖 cur
cur.val = tmp.val;
}
return cur;
}
/* 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） */
@ -153,7 +153,7 @@ public class binary_search_tree {
System.out.println("\n查找到的节点对象为 " + node + "，节点值 = " + node.val);
/* 插入节点 */
node = bst.insert(16);
bst.insert(16);
System.out.println("\n插入节点 16 后，二叉树为\n");
PrintUtil.printTree(bst.getRoot());