SOLUTIONS
LEETCODE.
Analysis and solutions for algorithmic problems.
| Problem | Difficulty | Complexity | Date |
|---|---|---|---|
| 0220 Contains Duplicate III | Hard | T: O(N) where N is the length of the array / S: O(min(N, indexDiff)) for the bucket map | Mar 2026 |
| 0224 Basic Calculator | Hard | T: O(N) where N is the length of the string / S: O(N) for the stack in the worst case of nested parentheses | Mar 2026 |
| 0233 Number of Digit One | Hard | T: O(log N) where N is the input number / S: O(1) constant extra space | Mar 2026 |
| 0239 Sliding Window Maximum | Hard | T: O(N) where N is the length of the array / S: O(K) where K is the window size | Mar 2026 |
| 0273 Integer to English Words | Hard | T: O(1) since the input is bounded by 2^31 - 1 (at most 10 digits) / S: O(1) for the same reason | Mar 2026 |
| 0282 Expression Add Operators | Hard | T: O(N * 4^N) where N is the length of the string / S: O(N) for the recursion depth | Mar 2026 |
| 0295 Find Median from Data Stream | Hard | T: O(log N) per insertion, O(1) per median query / S: O(N) where N is the total number of inserted elements | Mar 2026 |
| 0297 Serialize and Deserialize Binary Tree | Hard | T: O(N) where N is the number of nodes in the tree / S: O(N) for storing the serialized string and the recursion stack | Mar 2026 |
| 0301 Remove Invalid Parentheses | Hard | T: O(2^N) where N is the length of the string / S: O(N) for the recursion depth and the expression being built | Mar 2026 |
| 0312 Burst Balloons | Hard | T: O(N^3) / S: O(N^2) | Mar 2026 |
| 0315 Count of Smaller Numbers After Self | Hard | T: O(N log N) where N is the length of the array / S: O(N) for the temporary merge buffer and index tracking | Mar 2026 |
| 0321 Create Maximum Number | Hard | T: O(K * (M + N)) where M and N are the lengths of the two arrays / S: O(M + N) | Mar 2026 |
| 0327 Count of Range Sum | Hard | T: O(N log N) where N is the length of the array / S: O(N) for the prefix sum array and the merge buffer | Mar 2026 |
| 0329 Longest Increasing Path in a Matrix | Hard | T: O(M * N) where M and N are the dimensions of the matrix / S: O(M * N) | Mar 2026 |
| 0330 Patching Array | Hard | T: O(M + log N) where M is the length of nums and N is the target / S: O(1) | Mar 2026 |
| 0332 Reconstruct Itinerary | Hard | T: O(E log E) where E is the number of tickets / S: O(E) | Mar 2026 |
| 0335 Self Crossing | Hard | T: O(n) where n is the length of the distance array / S: O(1) | Mar 2026 |
| 0336 Palindrome Pairs | Hard | T: O(N * K^2) / S: O(N * K) | Mar 2026 |
| 0352 Data Stream as Disjoint Intervals | Hard | T: O(log N) per addNum, O(N) per getIntervals, where N is the number of intervals / S: O(N) | Mar 2026 |
| 0354 Russian Doll Envelopes | Hard | T: O(N log N) where N is the number of envelopes / S: O(N) | Mar 2026 |