Given a binary tree. Invert it. For each node:

• left child must become right child;
• right child must become left child;

Definition of a tree:

// Java
class TreeNode
{
public:
  int val;
  TreeNode left;
  TreeNode right;
  TreeNode(int x) {
    val = x;
    left = NULL; 
    right = NULL;
};

// C++
class TreeNode
{
public:
  int val;
  TreeNode *left;
  TreeNode *right;
  TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

Implement function Invert that returns the pointer to the inverted tree.

// Java
TreeNode Invert(TreeNode tree)

// C++
TreeNode* Invert(TreeNode *tree)

Example

Function Invert returns res - pointer to the inverted tree.