### Leetcode June Challenge - Day 1

**Problem:** LeetCode June Challenge - Day 1

**Ideas:**

- The problem is really simple, you just need to swap left and right for every node, as a tree is inverted iff every subtree is inverted.

**Solution**:

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