操作给定的二叉树，将其变换为源二叉树的镜像。
二叉树的镜像定义：源二叉树
8
/ \
6 10
/ \ / \
5 7 9 11
镜像二叉树
8
/ \
10 6
/ \ / \
11 9 7 5
思路：
1.左子树赋给temp
2.temp赋给右子树
3.右子树赋给左子树
4.递归
mirror(root)
temp=root->left
root->left=root->right
root-right=temp
mirror(root->left)
mirror(root->right)
class TreeNode{
var $val;
var $left = NULL;
var $right = NULL;
function __construct($val){
$this->val = $val;
}
}
function Mirror(&$root){
if($root==null){
return null;
}
$temp=$root->left;
$root->left=$root->right;
$root->right=$temp;
Mirror($root->left);
Mirror($root->right);
}
//构造一个树
$node5=new TreeNode(5);
$node7=new TreeNode(7);
$node9=new TreeNode(9);
$node11=new TreeNode(11);
$node6=new TreeNode(6);
$node10=new TreeNode(10);
$node8=new TreeNode(8);
$node8->left=$node6;
$node8->right=$node10;
$node6->left=$node5;
$node6->right=$node7;
$node10->left=$node9;
$node10->right=$node11;
$tree=$node8;
//镜像这棵二叉树
var_dump($tree);
Mirror($tree);
var_dump($tree);
object(TreeNode)#7 (3) {
["val"]=>
int(8)
["left"]=>
object(TreeNode)#5 (3) {
["val"]=>
int(6)
["left"]=>
object(TreeNode)#1 (3) {
["val"]=>
int(5)
["left"]=>
NULL
["right"]=>
NULL
}
["right"]=>
object(TreeNode)#2 (3) {
["val"]=>
int(7)
["left"]=>
NULL
["right"]=>
NULL
}
}
["right"]=>
object(TreeNode)#6 (3) {
["val"]=>
int(10)
["left"]=>
object(TreeNode)#3 (3) {
["val"]=>
int(9)
["left"]=>
NULL
["right"]=>
NULL
}
["right"]=>
object(TreeNode)#4 (3) {
["val"]=>
int(11)
["left"]=>
NULL
["right"]=>
NULL
}
}
object(TreeNode)#7 (3) {
["val"]=>
int(8)
["left"]=>
object(TreeNode)#6 (3) {
["val"]=>
int(10)
["left"]=>
object(TreeNode)#4 (3) {
["val"]=>
int(11)
["left"]=>
NULL
["right"]=>
NULL
}
["right"]=>
object(TreeNode)#3 (3) {
["val"]=>
int(9)
["left"]=>
NULL
["right"]=>
NULL
}
}
["right"]=>
object(TreeNode)#5 (3) {
["val"]=>
int(6)
["left"]=>
object(TreeNode)#2 (3) {
["val"]=>
int(7)
["left"]=>
NULL
["right"]=>
NULL
}
["right"]=>
object(TreeNode)#1 (3) {
["val"]=>
int(5)
["left"]=>
NULL
["right"]=>
NULL
}
}
}