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题目描述
操作给定的二叉树,将其变换为源二叉树的镜像。
思路
递归交换左右子树即可,必须是先序遍历或后序列遍历。
代码一(后序遍历):
/**
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){
Mirror(root.left);
Mirror(root.right);
TreeNode tmp = root.left;
root.left = root.right;
root.right = tmp;
}
}
}
代码二(先序遍历):
/**
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){
TreeNode tmp = root.left;
root.left = root.right;
root.right = tmp;
Mirror(root.left);
Mirror(root.right);
}
}
}