Problem
Given the root of a binary tree, invert the tree, and return its root.
Input
root of a binary tree
Output
Invert the binary tree, and return its root.
Constraints
- 0 <= Number of Nodes in the Tree ≤ 100
- -100 <= Value of Nodes ≤ 100
Sample Input
root = [10, 2, 21]
Sample Output
[10, 21, 2]
Code Implementation
class Solution {
public:
void solve (TreeNode *root) {
if (root == NULL) {
return;
}
TreeNode *temp = root->left;
root->left = root->right;
root->right = temp;
solve (root->left);
solve (root->right);
}
TreeNode* invertTree(TreeNode* root) {
solve(root);
return root;
}
};
Time Complexity: O(n)
Space Complexity: O(1) (without considering recursive stack)