Leetcode

Leetcode solution

1. Two Sum.md  [easy]
2. Add Two Numbers.md  [medium]
3. Longest Substring Without Repeating Characters.md  [medium]
5. Longest Palindromic Substring.md  [medium]
6. ZigZag Conversion.md  [medium]
7. Reverse Integer.md  [easy]
8. String to Integer (atoi).md  [medium]
9. Palindrome Number.md  [easy]
11. Container With Most Water.md  [medium]
12. Integer to Roman.md  [medium]
15. 3Sum.md  [medium]
16. 3Sum Closest.md  [medium]
17. Letter Combinations of a Phone Number.md  [medium]
18. 4Sum.md  [medium]
19. Remove Nth Node From End of List.md  [medium]
22. Generate Parentheses.md  [medium]
23. Merge k Sorted Lists.md  [hard]
24. Swap Nodes in Pairs.md  [medium]
25. Reverse Nodes in k-Group.md  [hard]
26. Remove Duplicates from Sorted Array.md  [easy]
27. Remove Element.md  [easy]
29. Divide Two Integers.md  [medium]
31. Next Permutation.md  [medium]
33. Search in Rotated Sorted Array.md  [medium]
34. Find First and Last Position of Element in Sorted Array.md  [medium]
35. Search Insert Position.md  [easy]
36. Valid Sudoku.md  [medium]
38. Count and Say.md  [easy]
39. Combination Sum.md  [medium]
40. Combination Sum II.md  [medium]
42. Trapping Rain Water.md  [hard]
43. Multiply Strings.md  [medium]
46. Permutations.md  [medium]
47. Permutations II.md  [medium]
48. Rotate Image.md  [medium]
49. Group Anagrams.md  [medium]
50. Pow(x, n).md  [medium]
53. Maximum Subarray.md  [easy]
54. Spiral Matrix.md  [medium]
55. Jump Game.md  [medium]
56. Merge Intervals.md  [medium]
57. Insert Interval.md  [hard]
58. Length of Last Word.md  [easy]
59. Spiral Matrix II.md  [medium]
60. Permutation Sequence.md  [medium]
61. Rotate List.md  [medium]
62. Unique Paths.md  [medium]
63. Unique Paths II.md  [medium]
64. Minimum Path Sum.md  [medium]
66. Plus One.md  [easy]
67. Add Binary.md  [easy]
69. Sqrt(x).md  [easy]
70. Climbing Stairs.md  [easy]
71. Simplify Path.md  [medium]
73. Set Matrix Zeroes.md  [medium]
74. Search a 2D Matrix.md  [medium]
75. Sort Colors.md  [medium]
77. Combinations.md  [medium]
78. Subsets.md  [medium]
79. Word Search.md  [medium]
80. Remove Duplicates from Sorted Array II.md  [medium]
81. Search in Rotated Sorted Array II.md  [medium]
82. Remove Duplicates from Sorted List II.md  [medium]
83. Remove Duplicates from Sorted List.md  [easy]
86. Partition List.md  [medium]
88. Merge Sorted Array.md  [easy]
89. Gray Code.md  [medium]
90. Subsets II.md  [medium]
91. Decode Ways.md  [medium]
92. Reverse Linked List II.md  [medium]
93. Restore IP Addresses.md  [medium]
94. Binary Tree Inorder Traversal.md  [medium]
95. Unique Binary Search Trees II.md  [medium]
96. Unique Binary Search Trees.md  [medium]
98. Validate Binary Search Tree.md  [medium]
100. Same Tree.md  [easy]
101. Symmetric Tree.md  [easy]
102. Binary Tree Level Order Traversal.md  [medium]
103. Binary Tree Zigzag Level Order Traversal.md  [medium]
104. Maximum Depth of Binary Tree.md  [easy]
105. Construct Binary Tree from Preorder and Inorder Traversal.md  [medium]
106. Construct Binary Tree from Inorder and Postorder Traversal.md  [medium]
107. Binary Tree Level Order Traversal II.md  [easy]
108. Convert Sorted Array to Binary Search Tree.md  [easy]
109. Convert Sorted List to Binary Search Tree.md  [medium]
110. Balanced Binary Tree.md  [easy]
111. Minimum Depth of Binary Tree.md  [easy]
112. Path Sum.md  [easy]
113. Path Sum II.md  [medium]
114. Flatten Binary Tree to Linked List.md  [medium]
116. Populating Next Right Pointers in Each Node.md  [medium]
117. Populating Next Right Pointers in Each Node II.md  [medium]
118. Pascal's Triangle.md  [easy]
119. Pascal's Triangle II.md  [easy]
120. Triangle.md  [medium]
121. Best Time to Buy and Sell Stock.md  [easy]
122. Best Time to Buy and Sell Stock II.md  [easy]
125. Valid Palindrome.md  [easy]
127. Word Ladder.md  [medium]
129. Sum Root to Leaf Numbers.md  [medium]
130. Surrounded Regions.md  [medium]
131. Palindrome Partitioning.md  [medium]
133. Clone Graph.md  [medium]
134. Gas Station.md  [medium]
136. Single Number.md  [easy]
137. Single Number II.md  [medium]
138. Copy List with Random Pointer.md  [medium]
139. Word Break.md  [medium]
141. Linked List Cycle.md  [easy]
143. Reorder List.md  [medium]
144. Binary Tree Preorder Traversal.md  [medium]
146. LRU Cache.md  [medium]
147. Insertion Sort List.md  [medium]
148. Sort List.md  [medium]
150. Evaluate Reverse Polish Notation.md  [medium]
151. Reverse Words in a String.md  [medium]
152. Maximum Product Subarray.md  [medium]
155. Min Stack.md  [easy]
160. Intersection of Two Linked Lists.md  [easy]
162. Find Peak Element.md  [medium]
165. Compare Version Numbers.md  [medium]
166. Fraction to Recurring Decimal.md  [medium]
167. Two Sum II - Input array is sorted.md  [easy]
168. Excel Sheet Column Title.md  [easy]
169. Majority Element.md  [easy]
171. Excel Sheet Column Number.md  [easy]
172. Factorial Trailing Zeroes.md  [easy]
173. Binary Search Tree Iterator.md  [medium]
175. Combine Two Tables.md  [easy]
176. Second Highest Salary.md  [easy]
177. Nth Highest Salary.md  [medium]
178. Rank Scores.md  [medium]
179. Largest Number.md  [medium]
180. Consecutive Numbers.md  [medium]
181. Employees Earning More Than Their Managers.md  [easy]
182. Duplicate Emails.md  [easy]
183. Customers Who Never Order.md  [easy]
184. Department Highest Salary.md  [medium]
187. Repeated DNA Sequences.md  [medium]
189. Rotate Array.md  [easy]
190. Reverse Bits.md  [easy]
191. Number of 1 Bits.md  [easy]
193. Valid Phone Numbers.md  [easy]
195. Tenth Line.md  [easy]
196. Delete Duplicate Emails.md  [easy]
197. Rising Temperature.md  [easy]
198. House Robber.md  [easy]
199. Binary Tree Right Side View.md  [medium]
200. Number of Islands.md  [medium]
201. Bitwise AND of Numbers Range.md  [medium]
202. Happy Number.md  [easy]
203. Remove Linked List Elements.md  [easy]
204. Count Primes.md  [easy]
205. Isomorphic Strings.md  [easy]
206. Reverse Linked List.md  [easy]
207. Course Schedule.md  [medium]
208. Implement Trie.md  [medium]
209. Minimum Size Subarray Sum.md  [medium]
211. Add and Search Word - Data structure design.md  [medium]
213. House Robber II.md  [medium]
215. Kth Largest Element in an Array.md  [medium]
217. Contains Duplicate.md  [easy]
219. Contains Duplicate II.md  [easy]
220. Contains Duplicate III.md  [medium]
225. Implement Stack using Queues.md  [easy]
226. Invert Binary Tree.md  [easy]
227. Basic Calculator II.md  [medium]
228. Summary Ranges.md  [medium]
229. Majority Element II.md  [medium]
230. Kth Smallest Element in a BST.md  [medium]
231. Power of Two.md  [easy]
232. Implement Queue using Stacks.md  [easy]
235. Lowest Common Ancestor of a Binary Search Tree.md  [easy]
236. Lowest Common Ancestor of a Binary Tree.md  [medium]
237. Delete Node in a Linked List.md  [easy]
238. Product of Array Except Self.md  [medium]
240. Search a 2D Matrix II.md  [medium]
257. Binary Tree Paths.md  [easy]
258. Add Digits.md  [easy]
260. Single Number III.md  [medium]
263. Ugly Number.md  [easy]
264. Ugly Number II.md  [medium]
268. Missing Number.md  [easy]
274. H-Index.md  [medium]
275. H-Index II.md  [medium]
278. First Bad Version.md  [easy]
283. Move Zeroes.md  [easy]
287. Find the Duplicate Number.md  [medium]
290. Word Pattern.md  [easy]
292. Nim Game.md  [easy]
299. Bulls and Cows.md  [easy]
303. Range Sum Query - Immutable.md  [easy]
326. Power of Three.md  [easy]
337. House Robber III.md  [medium]
342. Power of Four.md  [easy]
344. Reverse String.md  [easy]
345. Reverse Vowels of a String.md  [easy]
349. Intersection of Two Arrays.md  [easy]
350. Intersection of Two Arrays II.md  [easy]
367. Valid Perfect Square.md  [easy]
371. Sum of Two Integers.md  [easy]
374. Guess Number Higher or Lower.md  [easy]
383. Ransom Note.md  [easy]
387. First Unique Character in a String.md  [easy]
389. Find the Difference.md  [easy]
392. Is Subsequence.md  [easy]
401. Binary Watch.md  [easy]
404. Sum of Left Leaves.md  [easy]
405. Convert a Number to Hexadecimal.md  [easy]
409. Longest Palindrome.md  [easy]
414. Third Maximum Number.md  [easy]
415. Add Strings.md  [easy]
424. Longest Repeating Character Replacement.md  [medium]
429. N-ary Tree Level Order Traversal.md  [easy]
430. Flatten a Multilevel Doubly Linked List.md  [medium]
434. Number of Segments in a String.md  [easy]
437. Path Sum III.md  [easy]
441. Arranging Coins.md  [easy]
442. Find All Duplicates in an Array.md  [medium]
443. String Compression.md  [easy]
445. Add Two Numbers II.md  [medium]
447. Number of Boomerangs.md  [easy]
448. Find All Numbers Disappeared in an Array.md  [easy]
449. Serialize and Deserialize BST.md  [medium]
450. Delete Node in a BST.md  [medium]
453. Minimum Moves to Equal Array Elements.md  [easy]
455. Assign Cookies.md  [easy]
459. Repeated Substring Pattern.md  [easy]
461. Hamming Distance.md  [easy]
463. Island Perimeter.md  [easy]
475. Heaters.md  [easy]
476. Number Complement.md  [easy]
482. License Key Formatting.md  [easy]
485. Max Consecutive Ones.md  [easy]
491. Increasing Subsequences.md  [medium]
492. Construct the Rectangle.md  [easy]
496. Next Greater Element I.md  [easy]
500. Keyboard Row.md  [easy]
501. Find Mode in Binary Search Tree.md  [easy]
504. Base 7.md  [easy]
506. Relative Ranks.md  [easy]
507. Perfect Number.md  [easy]
508. Most Frequent Subtree Sum.md  [medium]
509. Fibonacci Number.md  [easy]
513. Find Bottom Left Tree Value.md  [medium]
515. Find Largest Value in Each Tree Row.md  [medium]
520. Detect Capital.md  [easy]
521. Longest Uncommon Subsequence I.md  [easy]
524. Longest Word in Dictionary through Deleting.md  [medium]
530. Minimum Absolute Difference in BST.md  [easy]
532. K-diff Pairs in an Array.md  [easy]
538. Convert BST to Greater Tree.md  [easy]
541. Reverse String II.md  [easy]
543. Diameter of Binary Tree.md  [easy]
551. Student Attendance Record I.md  [easy]
557. Reverse Words in a String III.md  [easy]
558. Quad Tree Intersection.md  [easy]
559. Maximum Depth of N-ary Tree.md  [easy]
561. Array Partition I.md  [easy]
563. Binary Tree Tilt.md  [easy]
566. Reshape the Matrix.md  [easy]
572. Subtree of Another Tree.md  [easy]
575. Distribute Candies.md  [easy]
581. Shortest Unsorted Continuous Subarray.md  [easy]
589. N-ary Tree Preorder Traversal.md  [easy]
590. N-ary Tree Postorder Traversal.md  [easy]
594. Longest Harmonious Subsequence.md  [easy]
595. Big Countries.md  [easy]
596. Classes More Than 5 Students.md  [easy]
598. Range Addition II.md  [easy]
599. Minimum Index Sum of Two Lists.md  [easy]
605. Can Place Flowers.md  [easy]
606. Construct String from Binary Tree.md  [easy]
617. Merge Two Binary Trees.md  [easy]
620. Not Boring Movies.md  [easy]
623. Add One Row to Tree.md  [medium]
627. Swap Salary.md  [easy]
628. Maximum Product of Three Numbers.md  [easy]
633. Sum of Square Numbers.md  [easy]
637. Average of Levels in Binary Tree.md  [easy]
643. Maximum Average Subarray I.md  [easy]
645. Set Mismatch.md  [easy]
652. Find Duplicate Subtrees.md  [medium]
653. Two Sum IV - Input is a BST.md  [easy]
654. Maximum Binary Tree.md  [medium]
657. Robot Return to Origin.md  [easy]
658. Find K Closest Elements.md  [medium]
661. Image Smoother.md  [easy]
662. Maximum Width of Binary Tree.md  [medium]
665. Non-decreasing Array.md  [easy]
669. Trim a Binary Search Tree.md  [easy]
671. Second Minimum Node In a Binary Tree.md  [easy]
674. Longest Continuous Increasing Subsequence.md  [easy]
680. Valid Palindrome II.md  [easy]
682. Baseball Game.md  [easy]
686. Repeated String Match.md  [easy]
687. Longest Univalue Path.md  [easy]
690. Employee Importance.md  [easy]
693. Binary Number with Alternating Bits.md  [easy]
696. Count Binary Substrings.md  [easy]
697. Degree of an Array.md  [easy]
700. Search in a Binary Search Tree.md  [easy]
701. Insert into a Binary Search Tree.md  [medium]
703. Kth Largest Element in a Stream.md  [easy]
704. Binary Search.md  [easy]
705. Design HashSet.md  [easy]
706. Design HashMap.md  [easy]
707. Design Linked List.md  [easy]
709. To Lower Case.md  [easy]
717. 1-bit and 2-bit Characters.md  [easy]
720. Longest Word in Dictionary.md  [easy]
724. Find Pivot Index.md  [easy]
725. Split Linked List in Parts.md  [medium]
728. Self Dividing Numbers.md  [easy]
733. Flood Fill.md  [easy]
744. Find Smallest Letter Greater Than Target.md  [easy]
747. Largest Number At Least Twice of Others.md  [easy]
748. Shortest Completing Word.md  [easy]
752. Open the Lock.md  [medium]
754. Reach a Number.md  [easy]
762. Prime Number of Set Bits in Binary Representation.md  [easy]
766. Toeplitz Matrix.md  [easy]
771. Jewels and Stones.md  [easy]
783. Minimum Distance Between BST Nodes.md  [easy]
784. Letter Case Permutation.md  [easy]
788. Rotated Digits.md  [easy]
796. Rotate String.md  [easy]
804. Unique Morse Code Words.md  [easy]
806. Number of Lines To Write String.md  [easy]
811. Subdomain Visit Count.md  [easy]
812. Largest Triangle Area.md  [easy]
817. Linked List Components.md  [medium]
819. Most Common Word.md  [easy]
821. Shortest Distance to a Character.md  [easy]
824. Goat Latin.md  [easy]
830. Positions of Large Groups.md  [easy]
832. Flipping an Image.md  [easy]
836. Rectangle Overlap.md  [easy]
840. Magic Squares In Grid.md  [easy]
844. Backspace String Compare.md  [easy]
849. Maximize Distance to Closest Person.md  [easy]
852. Peak Index in a Mountain Array.md  [easy]
859. Buddy Strings.md  [easy]
860. Lemonade Change.md  [easy]
863. All Nodes Distance K in Binary Tree.md  [medium]
865. Smallest Subtree with all the Deepest Nodes.md  [medium]
867. Transpose Matrix.md  [easy]
868. Binary Gap.md  [easy]
872. Leaf-Similar Trees.md  [easy]
874. Walking Robot Simulation.md  [easy]
876. Middle of the Linked List.md  [easy]
883. Projection Area of 3D Shapes.md  [easy]
884. Uncommon Words from Two Sentences.md  [easy]
888. Fair Candy Swap.md  [easy]
892. Surface Area of 3D Shapes.md  [easy]
893. Groups of Special-Equivalent Strings.md  [easy]
896. Monotonic Array.md  [easy]
897. Increasing Order Search Tree.md  [easy]
905. Sort Array By Parity.md  [easy]
908. Smallest Range I.md  [easy]
914. X of a Kind in a Deck of Cards.md  [easy]
917. Reverse Only Letters.md  [easy]
922. Sort Array By Parity II.md  [easy]
925. Long Pressed Name.md  [easy]
929. Unique Email Addresses.md  [easy]
933. Number of Recent Calls.md  [easy]
937. Reorder Data in Log Files.md  [easy]
938. Range Sum of BST.md  [easy]
941. Valid Mountain Array.md  [easy]
942. DI String Match.md  [easy]
944. Delete Columns to Make Sorted.md  [easy]
949. Largest Time for Given Digits.md  [easy]
953. Verifying an Alien Dictionary.md  [easy]
961. N-Repeated Element in Size 2N Array.md  [easy]
965. Univalued Binary Tree.md  [easy]
968. Binary Tree Cameras.md  [medium]
970. Powerful Integers.md  [easy]
976. Largest Perimeter Triangle.md  [easy]
977. Squares of a Sorted Array.md  [easy]
985. Sum of Even Numbers After Queries.md  [easy]
989. Add to Array-Form of Integer.md  [easy]
993. Cousins in Binary Tree.md  [easy]
994. Rotting Oranges.md  [easy]
997. Find the Town Judge.md  [easy]
999. Available Captures for Rook.md  [easy]
1002. Find Common Characters.md  [easy]
1005. Maximize Sum Of Array After K Negations.md  [easy]
1009. Complement of Base 10 Integer.md  [easy]
1010. Pairs of Songs With Total Durations Divisible by 60.md  [easy]
1013. Partition Array Into Three Parts With Equal Sum.md  [easy]
1018. Binary Prefix Divisible By 5.md  [easy]
1019. Next Greater Node In Linked List.md  [medium]
1021. Remove Outermost Parentheses.md  [easy]
1022. Sum of Root To Leaf Binary Numbers.md  [easy]
1025. Divisor Game.md  [easy]
1026. Maximum Difference Between Node and Ancestor.md  [medium]
1028. Recover a Tree From Preorder Traversal.md  [hard]
1029. Two City Scheduling.md  [easy]
1030. Matrix Cells in Distance Order.md  [easy]
1033. Moving Stones Until Consecutive.md  [easy]
1037. Valid Boomerang.md  [easy]
1042. Flower Planting With No Adjacent.md  [easy]
1046. Last Stone Weight.md  [easy]
1047. Remove All Adjacent Duplicates In String.md  [easy]
1051. Height Checker.md  [easy]
1071. Greatest Common Divisor of Strings.md  [easy]
1078. Occurrences After Bigram.md  [easy]
1089. Duplicate Zeros.md  [easy]
1103. Distribute Candies to People.md  [easy]
1108. Defanging an IP Address.md  [easy]
1110. Delete Nodes And Return Forest.md  [medium]
1114. Print in Order.md  [easy]
1122. Relative Sort Array.md  [easy]
1123. Lowest Common Ancestor of Deepest Leaves.md  [medium]
1128. Number of Equivalent Domino Pairs.md  [easy]
1137. N-th Tribonacci Number.md  [easy]
1154. Day of the Year.md  [easy]
1160. Find Words That Can Be Formed by Characters.md  [easy]
1170. Compare Strings by Frequency of the Smallest Character.md  [easy]
1171. Remove Zero Sum Consecutive Nodes from Linked List.md  [medium]
1175. Prime Arrangements.md  [easy]
1179. Reformat Department Table.md  [easy]
1184. Distance Between Bus Stops.md  [easy]
1185. Day of the Week.md  [easy]
1189. Maximum Number of Balloons.md  [easy]
1200. Minimum Absolute Difference.md  [easy]
1207. Unique Number of Occurrences.md  [easy]
1217. Play with Chips.md  [easy]
1221. Split a String in Balanced Strings.md  [easy]
1232. Check If It Is a Straight Line.md  [easy]
1237. Find Positive Integer Solution for a Given Equation.md  [easy]
1252. Cells with Odd Values in a Matrix.md  [easy]
1260. Shift 2D Grid.md  [easy]
1281. Subtract the Product and Sum of Digits of an Integer.md  [easy]
1290. Convert Binary Number in a Linked List to Integer.md  [easy]
1295. Find Numbers with Even Number of Digits.md  [easy]
1299. Replace Elements with Greatest Element on Right Side.md  [easy]
1302. Deepest Leaves Sum.md  [medium]
1304. Find N Unique Integers Sum up to Zero.md  [easy]
1305. All Elements in Two Binary Search Trees.md  [medium]
1315. Sum of Nodes with Even-Valued Grandparent.md  [medium]
1323. Maximum 69 Number.md  [easy]
1325. Delete Leaves With a Given Value.md  [medium]
1339. Maximum Product of Splitted Binary Tree.md  [medium]
1346. Check If N and Its Double Exist.md  [easy]
1360. Number of Days Between Two Dates.md  [easy]
1367. Linked List in Binary Tree.md  [medium]
1374. Generate a String With Characters That Have Odd Counts.md  [easy]
1375. Bulb Switcher III.md  [medium]
1376. Time Needed to Inform All Employees.md  [medium]
1380. Lucky Numbers in a Matrix.md  [easy]
1422. Maximum Score After Splitting a String.md  [easy]
1436. Destination City.md  [easy]
1437. Check If All 1's Are at Least Length K Places Away.md  [easy]
1450. Number of Students Doing Homework at a Given Time.md  [easy]
1455. Check If a Word Occurs As a Prefix of Any Word in a Sentence.md  [easy]
1460. Make Two Arrays Equal by Reversing Sub-arrays.md  [easy]
1464. Maximum Product of Two Elements in an Array.md  [easy]
1470. Shuffle the Array.md  [easy]
1480. Running Sum of 1d Array.md  [easy]
1491. Average Salary Excluding the Minimum and Maximum Salary.md  [easy]
1669. Merge In Between Linked Lists.md  [medium]
1721. Swapping Nodes in a Linked List.md  [medium]
1859. Sorting the Sentence.md  [easy]
1869. Longer Contiguous Segments of Ones than Zeros.md  [easy]
1876. Substrings of Size Three with Distinct Characters.md  [easy]
1893. Check if All the Integers in a Range Are Covered.md  [easy]
1979. Find Greatest Common Divisor of Array.md  [easy]
1985. Find the Kth Largest Integer in the Array.md  [easy]
1991. Find the Middle Index in Array.md  [easy]
2000. Reverse Prefix of Word.md  [easy]
2085. Count Common Words With One Occurrence.md  [easy]
2089. Find Target Indices After Sorting Array.md  [easy]
2185. Counting Words With a Given Prefix.md  [easy]
2190. Most Frequent Number Following Key In an Array.md  [easy]
2200. Find All K-Distant Indices in an Array.md  [easy]
2206. Divide Array Into Equal Pairs.md  [easy]
2215. Find the Difference of Two Arrays.md  [easy]
2248. Intersection of Multiple Arrays.md  [easy]
2255. Count Prefixes of a Given String.md  [easy]
2264. Largest 3-Same-Digit Number in String.md  [easy]
2309. Greatest English Letter in Upper and Lower Case.md  [easy]
2315. Count Asterisks.md  [easy]
2319. Check if Matrix Is X-Matrix.md  [easy]
2331. Evaluate Boolean Binary Tree.md  [easy]
2335. Minimum Amount of Time to Fill Cups.md  [easy]
2336. Smallest Number in Infinite Set.md  [medium]
2337. Move Pieces to Obtain a String.md  [medium]
2341. Maximum Number of Pairs in Array.md  [easy]
2342. Max Sum of a Pair With Equal Sum of Digits.md  [medium]
2343. Query Kth Smallest Trimmed Number.md  [medium]
2344. Minimum Deletions to Make Array Divisible.md  [hard]
2347. Best Poker Hand.md  [easy]
2348. Number of Zero-Filled Subarrays.md  [medium]
2349. Design a Number Container System.md  [medium]
2351. First Letter to Appear Twice.md  [easy]
2352. Equal Row and Column Pairs.md  [medium]
2353. Design a Food Rating System.md  [medium]
2354. Number of Excellent Pairs.md  [hard]
2357. Make Array Zero by Subtracting Equal Amounts.md  [easy]
2404. Most Frequent Even Element.md  [easy]  
2405. Optimal Partition of String.md  [easy]