LeetCode 之 Invert Binary Tree

struct TreeNode *invertTree(struct TreeNode *root)
{
struct TreeNode *tmp = NULL;

if (root == NULL)
{
return NULL;
}

//!< 先交换左右节点，再分别对左右节点递归
tmp = root->right;
root->right = root->left;
root->left  = tmp;

if (root->right)
{
invertTree(root->right);
}

if (root->left)
{
invertTree(root->left);
}

return root;
}