Invert Binary Tree

该题比较简单，递归交换每一个节点的左右子树即可。

class Solution {
public:
    TreeNode* invertTree(TreeNode* root) {
        if(root == NULL)
            return NULL;
        TreeNode* tmp = root -> left;
        root -> left = invertTree(root -> right);
        root -> right = invertTree(tmp);

    }
};

Invert Binary Tree

原文：http://blog.csdn.net/ny_mg/article/details/46876493