操作给定的二叉树，将其变换为源二叉树的镜像。
源二叉树
8
/ \
6 10
/ \ / \
5 7 9 11
镜像二叉树
8
/ \
10 6
/ \ / \
11 9 7 5
代码
- 递归
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public void Mirror(TreeNode root) {
if (root == null) {
return;
}
TreeNode temp = root.left;
root.left = root.right;
root.right = temp;
Mirror(root.left);
Mirror(root.right);
}
}
- 非递归用栈
import java.util.Stack;
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public void Mirror(TreeNode root) {
if (root == null) {
return;
}
Stack<TreeNode> stack = new Stack<>();
stack.push(root);
while (!stack.isEmpty()) {
TreeNode node = stack.pop();
TreeNode temp = node.left;
node.left = node.right;
node.right = temp;
if (node.left != null) {
stack.push(node.left);
}
if (node.right != null) {
stack.push(node.right);
}
}
}
}
