My leetcode solutions

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• My leetcode solutions
  • Easy Tasks
  • Medium Tasks
  • Hard Tasks

Easy Tasks

1. 1. Two Sum
2. 1480. Running Sum of 1d Array
3. 205. Isomorphic Strings
4. 392. Is Subsequence
5. 724. Find Pivot Index
6. 21. Merge Two Sorted Lists
7. 206. Reverse Linked List
8. 876. Middle of the Linked List
9. 121. Best Time to Buy and Sell Stock
10. 409. Longest Palindrome
11. 589. N-ary Tree Preorder Traversal
12. 704. Binary Search
13. 278. First Bad Version
14. 509. Fibonacci Number
15. 70. Climbing Stairs
16. 844. Backspace String Compare
17. 242. Valid Anagram
18. 26. Remove Duplicates from Sorted Array
19. 2614. Prime In Diagonal
20. 2605. Form Smallest Number From Two Digit Arrays
21. 2586. Count the Number of Vowel Strings in Range
22. 2570. Merge Two 2D Arrays by Summing Values
23. 2574. Left and Right Sum Differences
24. 1768. Merge Strings Alternately
25. 2562. Find the Array Concatenation Value
26. 2037. Minimum Number of Moves to Seat Everyone
27. 917. Reverse Only Letters
28. 27. Remove Element
29. 66. Plus One
30. 485. Max Consecutive Ones
31. 219. Contains Duplicate II
32. 14. Longest Common Prefix
33. 575. Distribute Candies
34. 1572. Matrix Diagonal Sum
35. 1351. Count Negative Numbers in a Sorted Matrix
36. 125. Valid Palindrome
37. 344. Reverse String
38. 283. Move Zeroes
39. 1700. Number of Students Unable to Eat Lunch
40. 20. Valid Parentheses
41. 1047. Remove All Adjacent Duplicates In String
42. 1544. Make The String Great
43. 338. Counting Bits
44. 746. Min Cost Climbing Stairs
45. 35. Search Insert Position
46. 69. Sqrt(x)
47. 268. Missing Number
48. 326. Power of Three
49. 231. Power of Two
50. 342. Power of Four
51. 1346. Check If N and Its Double Exist
52. 350. Intersection of Two Arrays II
53. 1437. Check If All 1's Are at Least Length K Places Away
54. 1337. The K Weakest Rows in a Matrix
55. 1876. Substrings of Size Three with Distinct Characters
56. 643. Maximum Average Subarray I
57. 1518. Water Bottles
58. 2190. Most Frequent Number Following Key In an Array
59. 2085. Count Common Words With One Occurrence
60. 2248. Intersection of Multiple Arrays
61. 1365. How Many Numbers Are Smaller Than the Current Number
62. 1128. Number of Equivalent Domino Pairs
63. 2733. Neither Minimum nor Maximum
64. 1837. Sum of Digits in Base K
65. 1290. Convert Binary Number in a Linked List to Integer
66. 9. Palindrome Number
67. 13. Roman to Integer
68. 160. Intersection of Two Linked Lists
69. 705. Design HashSet
70. 706. Design HashMap
71. 83. Remove Duplicates from Sorted List
72. 234. Palindrome Linked List
73. 141. Linked List Cycle
74. 203. Remove Linked List Elements
75. 2529. Maximum Count of Positive Integer and Negative Integer
76. 476. Number Complement
77. 226. Invert Binary Tree
78. 104. Maximum Depth of Binary Tree
79. 1945. Sum of Digits of String After Convert
80. 1108. Defanging an IP Address
81. 507. Perfect Number
82. 100. Same Tree
83. 543. Diameter of Binary Tree
84. 1957. Delete Characters to Make Fancy String
85. 110. Balanced Binary Tree
86. 572. Subtree of Another Tree
87. 2235. Add Two Integers
88. 2540. Minimum Common Value
89. 598. Range Addition II
90. 136. Single Number
91. 1071. Greatest Common Divisor of Strings
92. 1431. Kids With the Greatest Number of Candies
93. 605. Can Place Flowers
94. 345. Reverse Vowels of a String
95. 1732. Find the Highest Altitude
96. 2215. Find the Difference of Two Arrays
97. 1207. Unique Number of Occurrences
98. 349. Intersection of Two Arrays
99. 933. Number of Recent Calls
100. 872. Leaf-Similar Trees
101. 144. Binary Tree Preorder Traversal
102. 94. Binary Tree Inorder Traversal
103. 225. Implement Stack using Queues
104. 700. Search in a Binary Search Tree
105. 1848. Minimum Distance to the Target Element
106. 169. Majority Element
107. 118. Pascal's Triangle
108. 1704. Determine if String Halves Are Alike
109. 1748. Sum of Unique Elements
110. 1403. Minimum Subsequence in Non-Increasing Order
111. 680. Valid Palindrome II
112. 2578. Split With Minimum Sum
113. 1523. Count Odd Numbers in an Interval Range
114. 897. Increasing Order Search Tree
115. 2651. Calculate Delayed Arrival Time
116. 1791. Find Center of Star Graph
117. 997. Find the Town Judge
118. 561. Array Partition
119. 2180. Count Integers With Even Digit Sum
120. 1299. Replace Elements with Greatest Element on Right Side
121. 389. Find the Difference
122. 374. Guess Number Higher or Lower
123. 905. Sort Array By Parity
124. 896. Monotonic Array
125. 557. Reverse Words in a String III
126. 1512. Number of Good Pairs
127. 2413. Smallest Even Multiple
128. 965. Univalued Binary Tree
129. 617. Merge Two Binary Trees
130. 119. Pascal's Triangle II
131. 1984. Minimum Difference Between Highest and Lowest of K Scores
132. 530. Minimum Absolute Difference in BST
133. 1662. Check If Two String Arrays are Equivalent
134. 1929. Concatenation of Array
135. 1832. Check if the Sentence Is Pangram
136. 387. First Unique Character in a String
137. 383. Ransom Note
138. 884. Uncommon Words from Two Sentences
139. 819. Most Common Word
140. 1636. Sort Array by Increasing Frequency
141. 2506. Count Pairs Of Similar Strings
142. 501. Find Mode in Binary Search Tree
143. 1356. Sort Integers by The Number of 1 Bits
144. 744. Find Smallest Letter Greater Than Target
145. 2185. Counting Words With a Given Prefix
146. 2351. First Letter to Appear Twice
147. 1539. Kth Missing Positive Number
148. 1408. String Matching in an Array
149. 922. Sort Array By Parity II
150. 2239. Find Closest Number to Zero
151. 2283. Check if Number Has Equal Digit Count and Digit Value
152. 1460. Make Two Arrays Equal by Reversing Subarrays
153. 2496. Maximum Value of a String in an Array
154. 1684. Count the Number of Consistent Strings
155. 28. Find the Index of the First Occurrence in a String
156. 2744. Find Maximum Number of String Pairs
157. 1672. Richest Customer Wealth
158. 2160. Minimum Sum of Four Digit Number After Splitting Digits
159. 448. Find All Numbers Disappeared in an Array
160. 191. Number of 1 Bits
161. 303. Range Sum Query - Immutable
162. 111. Minimum Depth of Binary Tree
163. 1160. Find Words That Can Be Formed by Characters
164. 2264. Largest 3-Same-Digit Number in String
165. 1688. Count of Matches in Tournament
166. 1903. Largest Odd Number in String
167. 867. Transpose Matrix
168. 2206. Divide Array Into Equal Pairs
169. 1287. Element Appearing More Than 25% In Sorted Array
170. 1464. Maximum Product of Two Elements in an Array
171. 1582. Special Positions in a Binary Matrix
172. 1436. Destination City
173. 637. Average of Levels in Binary Tree
174. 1913. Maximum Product Difference Between Two Pairs
175. 2706. Buy Two Chocolates
176. 653. Two Sum IV - Input is a BST
177. 1496. Path Crossing
178. 2011. Final Value of Variable After Performing Operations
179. 2974. Minimum Number Game
180. 1897. Redistribute Characters to Make All Strings Equal
181. 455. Assign Cookies
182. 2932. Maximum Strong Pair XOR I
183. 938. Range Sum of BST
184. 1502. Can Make Arithmetic Progression From Sequence
185. 2500. Delete Greatest Value in Each Row
186. 2418. Sort the People
187. 2729. Check if The Number is Fascinating
188. 645. Set Mismatch
189. 2798. Number of Employees Who Met the Target
190. 232. Implement Queue using Stacks
191. 771. Jewels and Stones
192. 1603. Design Parking System
193. 709. To Lower Case
194. 2108. Find First Palindromic String in the Array
195. 2469. Convert the Temperature
196. 1678. Goal Parser Interpretation
197. 2824. Count Pairs Whose Sum is Less than Target
198. 222. Count Complete Tree Nodes
199. 1614. Maximum Nesting Depth of the Parentheses
200. 101. Symmetric Tree
201. 1816. Truncate Sentence
202. 671. Second Minimum Node In a Binary Tree
203. 1920. Build Array from Permutation
204. 1528. Shuffle String
205. 2652. Sum Multiples
206. 2520. Count the Digits That Divide a Number
207. 3005. Count Elements With Maximum Frequency
208. 258. Add Digits
209. 404. Sum of Left Leaves
210. 1967. Number of Strings That Appear as Substrings in Word
211. 2236. Root Equals Sum of Children
212. 2535. Difference Between Element Sum and Digit Sum of an Array
213. 2828. Check if a String Is an Acronym of Words
214. 2553. Separate the Digits in an Array
215. 2710. Remove Trailing Zeros From a String
216. 1991. Find the Middle Index in Array
217. 1281. Subtract the Product and Sum of Digits of an Integer
218. 2114. Maximum Number of Words Found in Sentences
219. 2000. Reverse Prefix of Word
220. 2788. Split Strings by Separator
221. 2363. Merge Similar Items
222. 1450. Number of Students Doing Homework at a Given Time
223. 1051. Height Checker
224. 2073. Time Needed to Buy Tickets
225. 1022. Sum of Root To Leaf Binary Numbers
226. 1470. Shuffle the Array
227. 67. Add Binary
228. 3110. Score of a String
229. 1773. Count Items Matching a Rule
230. 2325. Decode the Message
231. 1844. Replace All Digits with Characters
232. 1588. Sum of All Odd Length Subarrays
233. 1137. N-th Tribonacci Number
234. 2956. Find Common Elements Between Two Arrays
235. 3120. Count the Number of Special Characters I
236. 3046. Split the Array
237. 1389. Create Target Array in the Given Order
238. 1863. Sum of All Subset XOR Totals
239. 2441. Largest Positive Integer That Exists With Its Negative
240. 3131. Find the Integer Added to Array I
241. 3136. Valid Word
242. 506. Relative Ranks
243. 3146. Permutation Difference between Two Strings
244. 3099. Harshad Number
245. 2913. Subarrays Distinct Element Sum of Squares I

Medium Tasks

1. 142. Linked List Cycle II
2. 102. Binary Tree Level Order Traversal
3. 98. Validate Binary Search Tree
4. 2640. Find the Score of All Prefixes of an Array
5. 2610. Convert an Array Into a 2D Array With Conditions
6. 49. Group Anagrams
7. 347. Top K Frequent Elements
8. 151. Reverse Words in a String
9. 1209. Remove All Adjacent Duplicates in String II
10. 150. Evaluate Reverse Polish Notation
11. 739. Daily Temperatures
12. 167. Two Sum II - Input Array Is Sorted
13. 15. 3Sum
14. 33. Search in Rotated Sorted Array
15. 153. Find Minimum in Rotated Sorted Array
16. 1343. Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold
17. 2090. K Radius Subarray Averages
18. 1456. Maximum Number of Vowels in a Substring of Given Length
19. 713. Subarray Product Less Than K
20. 3. Longest Substring Without Repeating Characters
21. 1839. Longest Substring Of All Vowels in Order
22. 1358. Number of Substrings Containing All Three Characters
23. 12. Integer to Roman
24. 7. Reverse Integer
25. 19. Remove Nth Node From End of List
26. 143. Reorder List
27. 287. Find the Duplicate Number
28. 2181. Merge Nodes in Between Zeros
29. 230. Kth Smallest Element in a BST
30. 235. Lowest Common Ancestor of a Binary Search Tree
31. 1476. Subrectangle Queries
32. 1689. Partitioning Into Minimum Number Of Deci-Binary Numbers
33. 2396. Strictly Palindromic Number
34. 1302. Deepest Leaves Sum
35. 535. Encode and Decode TinyURL
36. 1008. Construct Binary Search Tree from Preorder Traversal
37. 48. Rotate Image
38. 567. Permutation in String
39. 128. Longest Consecutive Sequence
40. 155. Min Stack
41. 237. Delete Node in a Linked List
42. 451. Sort Characters By Frequency
43. 2442. Count Number of Distinct Integers After Reverse Operations
44. 443. String Compression
45. 334. Increasing Triplet Subsequence
46. 238. Product of Array Except Self
47. 11. Container With Most Water
48. 1679. Max Number of K-Sum Pairs
49. 1004. Max Consecutive Ones III
50. 1493. Longest Subarray of 1's After Deleting One Element
51. 1657. Determine if Two Strings Are Close
52. 2352. Equal Row and Column Pairs
53. 2390. Removing Stars From a String
54. 735. Asteroid Collision
55. 394. Decode String
56. 649. Dota2 Senate
57. 2095. Delete the Middle Node of a Linked List
58. 328. Odd Even Linked List
59. 2130. Maximum Twin Sum of a Linked List
60. 437. Path Sum III
61. 1372. Longest ZigZag Path in a Binary Tree
62. 236. Lowest Common Ancestor of a Binary Tree
63. 199. Binary Tree Right Side View
64. 450. Delete Node in a BST
65. 841. Keys and Rooms
66. 547. Number of Provinces
67. 1466. Reorder Routes to Make All Paths Lead to the City Zero
68. 399. Evaluate Division
69. 215. Kth Largest Element in an Array
70. 2336. Smallest Number in Infinite Set
71. 994. Rotting Oranges
72. 2542. Maximum Subsequence Score
73. 162. Find Peak Element
74. 229. Majority Element II
75. 34. Find First and Last Position of Element in Sorted Array
76. 137. Single Number II
77. 2807. Insert Greatest Common Divisors in Linked List
78. 515. Find Largest Value in Each Tree Row
79. 2433. Find The Original Array of Prefix Xor
80. 2023. Number of Pairs of Strings With Concatenation Equal to Target
81. 1535. Find the Winner of an Array Game
82. 2785. Sort Vowels in a String
83. 1980. Find Unique Binary String
84. 1877. Minimize Maximum Pair Sum in Array
85. 53. Maximum Subarray
86. 2482. Difference Between Ones and Zeros in Row and Column
87. 1557. Minimum Number of Vertices to Reach All Nodes
88. 1833. Maximum Ice Cream Bars
89. 1578. Minimum Time to Make Rope Colorful
90. 2870. Minimum Number of Operations to Make Array Empty
91. 2487. Remove Nodes From Linked List
92. 1026. Maximum Difference Between Node and Ancestor
93. 1347. Minimum Number of Steps to Make Two Strings Anagram
94. 2186. Minimum Number of Steps to Make Two Strings Anagram II
95. 2225. Find Players With Zero or One Losses
96. 380. Insert Delete GetRandom O(1)
97. 931. Minimum Falling Path Sum
98. 46. Permutations
99. 39. Combination Sum
100. 77. Combinations
101. 47. Permutations II
102. 78. Subsets
103. 1286. Iterator for Combination
104. 90. Subsets II
105. 216. Combination Sum III
106. 17. Letter Combinations of a Phone Number
107. 1472. Design Browser History
108. 1381. Design a Stack With Increment Operation
109. 2149. Rearrange Array Elements by Sign
110. 2545. Sort the Students by Their Kth Score
111. 1305. All Elements in Two Binary Search Trees
112. 1669. Merge In Between Linked Lists
113. 442. Find All Duplicates in an Array
114. 129. Sum Root to Leaf Numbers
115. 988. Smallest String Starting From Leaf
116. 1282. Group the People Given the Group Size They Belong To
117. 2265. Count Nodes Equal to Average of Subtree
118. 165. Compare Version Numbers
119. 881. Boats to Save People
120. 2816. Double a Number Represented as a Linked List
121. 3075. Maximize Happiness of Selected Children

Hard Tasks

1. 1206. Design Skiplist
2. 1531. String Compression II

to be continue...