Desicription
Invert a binary tree.
Example:
Input:
1
2
3
4
5
|
4
/
2 7
/ /
1 3 6 9
|
Output:
1
2
3
4
5
|
4
/
7 2
/ /
9 6 3 1
|
Trivia:
This problem was inspired by this original tweet by Max Howell:
Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tree on a whiteboard so f*** off.
Solution
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class {
public:
TreeNode* invertTree(TreeNode* root) {
if(root == nullptr) {
return nullptr;
}
auto left_node = invertTree(root->left);
auto right_node = invertTree(root->right);
root->left = right_node;
root->right = left_node;
return root;
}
};
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