77. CombinationsNode:Time Complexity && Space Complexity
Time Complexity: O(k * C(n, k))
there are C(n, k) times recu...
669. Trim a Binary Search TreeNode:Time Complexity && Space Complexity
Time Complexity: O(n)
Space Complexity: O()
Be...
235. Lowest Common Ancestor of a Binary Search TreeNode:Time Complexity && Space Complexity
Time Complexity: O(logn)
...
530. Minimum Absolute Difference in BSTNode:
Find the max and min of every node
Calculate the absolue diff for every node by ...
654. Maximum Binary TreeNode:Time Complexity && Space Complexity
Time Complexity:
Worst case: O(n*n)
Average case: O(...
106. Construct Binary Tree from Inorder and Postorder TraversalNode:
Get root from the postorder which is always the last one...
110. Balanced Binary TreeNode:Time Complexity && Space Complexity
Time Complexity: O(n)
Space Complexity: O(n)
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226. Invert Binary TreeNode:Time Complexity && Space Complexity
Time Complexity: O(n)
Space Complexity: O(n)
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144. Binary Tree Preorder TraversalNode:
Preorder: mid, left, right
Iterate: push the right node, then push the left node
Ti...
150. Evaluate Reverse Polish NotationNode:Time Complexity && Space Complexity
Time Complexity: O(n)
Space Complexity:...
