java中,使用栈实现二叉树三叉链表的非递归深拷贝构造,给我具体代码
时间: 2024-12-05 10:15:58 浏览: 15
在Java中,我们可以使用栈的数据结构来实现二叉树(包括三叉链表)的深度克隆,而非递归的方式。首先,我们需要创建三个辅助类分别代表节点、二叉树节点和三叉树节点。以下是具体的步骤和代码示例:
```java
// 定义基础节点类型
class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) { val = x; }
}
// 定义二叉树节点
class BinaryTreeNode extends TreeNode {
BinaryTreeNode(TreeNode original) {
this(original.val);
if (original.left != null) {
pushToStack(original.left);
}
while (!stack.isEmpty()) {
TreeNode node = stack.pop();
if (node.right != null) {
pushToStack(node.right);
}
cloneTree(this, node);
}
}
private Stack<TreeNode> stack = new Stack<>();
private void pushToStack(TreeNode node) {
if (node != null) {
stack.push(node);
}
}
private void cloneTree(TreeNode target, TreeNode source) {
if (source == null) return;
TreeNode newNode = new BinaryTreeNode(source);
target.left = newNode;
target.right = cloneTree(target.right, source.right);
}
}
// 定义三叉树节点
class TrieNode {
int val;
TrieNode left;
TrieNode middle;
TrieNode right;
TrieNode(int x) { val = x; }
}
// 三叉树的非递归深度复制
public class TrieNodeDeepCopy {
public static TrieNode deepClone(TrieNode root) {
if (root == null) return null;
TrieNode newNode = new TrieNode(root.val);
stack.push(newNode);
while (!stack.isEmpty()) {
TrieNode node = stack.pop();
if (node.left != null) {
stack.push(node.left);
}
if (node.middle != null) {
stack.push(node.middle);
}
if (node.right != null) {
stack.push(node.right);
}
copyChildNodes(node, newNode);
}
return newNode;
}
private Stack<TrieNode> stack = new Stack<>();
private void copyChildNodes(TrieNode src, TrieNode dst) {
TrieNode temp = src;
while (temp != null) {
TrieNode child = temp.left;
temp.left = dst.left;
dst.left = child;
if (child != null) {
stack.push(child);
}
child = temp.middle;
temp.middle = dst.middle;
dst.middle = child;
if (child != null) {
stack.push(child);
}
child = temp.right;
temp.right = dst.right;
dst.right = child;
if (child != null) {
stack.push(child);
}
temp = src.parent; // 如果有parent,则继续处理下一个兄弟节点
}
}
}
```
在这段代码中,我们使用了一个栈来存储待访问的节点,并通过循环逐层复制节点及其子节点。`pushToStack`用于将节点入栈,`cloneTree`或`copyChildNodes`负责实际的节点复制。注意,这里的三叉树版本需要额外处理parent指针来保持正确的父子关系。
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