剑指 Offer 27. 二叉树的镜像（反转二叉树）

函数返回该二叉树的镜像

class Solution {
    public TreeNode mirrorTree(TreeNode root) {
        if(root == null){
            return null;
        }
        TreeNode temp = root.left;
        root.left = mirrorTree(root.right);
        root.right = mirrorTree(temp);
        return root;
    }
}      

struct TreeNode{
    int val;
    TreeNode* left;
    TreeNode* right;
};
struct TreeNode* mirror(struct TreeNode* tree){
    if (tree == NULL){
        return NULL;
    }
    struct TreeNode* temp = tree->left;
    tree->left = mirror(tree->right);
    tree->right = mirror(tree->left);
    return tree;
}