/leetcode-java

763 solved problems with test cases and all common structures from https://leetcode.com on Java

Primary LanguageJava

leetcode-java

About

Some solved problems from LeetCode on Java.

Links

Profile on LeetCode: fartem.

Solutions

Easy

Name Link to LeetCode Link to solution
1. Two Sum Link Link
9. Palindrome Number Link Link
13. Roman to Integer Link Link
14. Longest Common Prefix Link Link
20. Valid Parentheses Link Link
21. Merge Two Sorted Lists Link Link
27. Remove Element Link Link
35. Search Insert Position Link Link
58. Length of Last Word Link Link
66. Plus One Link Link
67. Add Binary Link Link
69. Sqrt(x) Link Link
70. Climbing Stairs Link Link
83. Remove Duplicates from Sorted List Link Link
88. Merge Sorted Array Link Link
94. Binary Tree Inorder Traversal Link Link
100. Same Tree Link Link
101. Symmetric Tree Link Link
104. Maximum Depth of Binary Tree Link Link
108. Convert Sorted Array to Binary Search Tree Link Link
110. Balanced Binary Tree Link Link
111. Minimum Depth of Binary Tree Link Link
112. Path Sum Link Link
118. Pascal's Triangle Link Link
119. Pascal's Triangle II Link Link
121. Best Time to Buy and Sell Stock Link Link
125. Valid Palindrome Link Link
136. Single Number Link Link
141. Linked List Cycle Link Link
144. Binary Tree Preorder Traversal Link Link
145. Binary Tree Postorder Traversal Link Link
160. Intersection of Two Linked Lists Link Link
168. Excel Sheet Column Title Link Link
169. Majority Element Link Link
171. Excel Sheet Column Number Link Link
190. Reverse Bits Link Link
191. Number of 1 Bits Link Link
202. Happy Number Link Link
203. Remove Linked List Elements Link Link
205. Isomorphic Strings Link Link
206. Reverse Linked List Link Link
217. Contains Duplicate Link Link
219. Contains Duplicate II Link Link
225. Implement Stack using Queues Link Link
226. Invert Binary Tree Link Link
228. Summary Ranges Link Link
231. Power of Two Link Link
232. Implement Queue using Stacks Link Link
234. Palindrome Linked List Link Link
242. Valid Anagram Link Link
257. Binary Tree Paths Link Link
263. Ugly Number Link Link
258. Add Digits Link Link
268. Missing Number Link Link
278. First Bad Version Link Link
290. Word Pattern Link Link
292. Nim Game Link Link
303. Range Sum Query - Immutable Link Link
326. Power of Three Link Link
338. Counting Bits Link Link
342. Power of Four Link Link
344. Reverse String Link Link
345. Reverse Vowels of a String Link Link
349. Intersection of Two Arrays Link Link
350. Intersection of Two Arrays II Link Link
367. Valid Perfect Square Link Link
374. Guess Number Higher or Lower Link Link
383. Ransom Note Link Link
387. First Unique Character in a String Link Link
389. Find the Difference Link Link
392. Is Subsequence Link Link
404. Sum of Left Leaves Link Link
405. Convert a Number to Hexadecimal Link Link
409. Longest Palindrome Link Link
412. Fizz Buzz Link Link
414. Third Maximum Number Link Link
415. Add Strings Link Link
434. Number of Segments in a String Link Link
441. Arranging Coins Link Link
448. Find All Numbers Disappeared in an Array Link Link
455. Assign Cookies Link Link
459. Repeated Substring Pattern Link Link
461. Hamming Distance Link Link
463. Island Perimeter Link Link
476. Number Complement Link Link
482. License Key Formatting Link Link
485. Max Consecutive Ones Link Link
492. Construct the Rectangle Link Link
496. Next Greater Element I Link Link
500. Keyboard Row Link Link
501. Find Mode in Binary Search Tree Link Link
504. Base 7 Link Link
506. Relative Ranks Link Link
507. Perfect Number Link Link
509. Fibonacci Number Link Link
520. Detect Capital Link Link
521. Longest Uncommon Subsequence I Link Link
530. Minimum Absolute Difference in BST Link Link
543. Diameter of Binary Tree Link Link
551. Student Attendance Record I Link Link
557. Reverse Words in a String III Link Link
559. Maximum Depth of N-ary Tree Link Link
561. Array Partition Link Link
563. Binary Tree Tilt Link Link
566. Reshape the Matrix Link Link
572. Subtree of Another Tree Link Link
589. N-ary Tree Preorder Traversal Link Link
590. N-ary Tree Postorder Traversal Link Link
594. Longest Harmonious Subsequence Link Link
599. Minimum Index Sum of Two Lists Link Link
606. Construct String from Binary Tree Link Link
617. Merge Two Binary Trees Link Link
628. Maximum Product of Three Numbers Link Link
637. Average of Levels in Binary Tree Link Link
643. Maximum Average Subarray I Link Link
645. Set Mismatch Link Link
653. Two Sum IV - Input is a BST Link Link
657. Robot Return to Origin Link Link
671. Second Minimum Node In a Binary Tree Link Link
674. Longest Continuous Increasing Subsequence Link Link
680. Valid Palindrome II Link Link
682. Baseball Game Link Link
693. Binary Number with Alternating Bits Link Link
700. Search in a Binary Search Tree Link Link
703. Kth Largest Element in a Stream Link Link
704. Binary Search Link Link
705. Design HashSet Link Link
706. Design HashMap Link Link
709. To Lower Case Link Link
717. 1-bit and 2-bit Characters Link Link
724. Find Pivot Index Link Link
728. Self Dividing Numbers Link Link
733. Flood Fill Link Link
744. Find Smallest Letter Greater Than Target Link Link
746. Min Cost Climbing Stairs Link Link
747. Largest Number At Least Twice of Others Link Link
762. Prime Number of Set Bits in Binary Representation Link Link
766. Toeplitz Matrix Link Link
771. Jewels and Stones Link Link
783. Minimum Distance Between BST Nodes Link Link
796. Rotate String Link Link
804. Unique Morse Code Words Link Link
806. Number of Lines To Write String Link Link
812. Largest Triangle Area Link Link
819. Most Common Word Link Link
821. Shortest Distance to a Character Link Link
830. Positions of Large Groups Link Link
832. Flipping an Image Link Link
844. Backspace String Compare Link Link
859. Buddy Strings Link Link
860. Lemonade Change Link Link
867. Transpose Matrix Link Link
868. Binary Gap Link Link
872. Leaf-Similar Trees Link Link
876. Middle of the Linked List Link Link
884. Uncommon Words from Two Sentences Link Link
896. Monotonic Array Link Link
897. Increasing Order Search Tree Link Link
905. Sort Array By Parity Link Link
908. Smallest Range I Link Link
917. Reverse Only Letters Link Link
922. Sort Array By Parity II Link Link
925. Long Pressed Name Link Link
929. Unique Email Addresses Link Link
933. Number of Recent Calls Link Link
938. Range Sum of BST Link Link
941. Valid Mountain Array Link Link
942. DI String Match Link Link
944. Delete Columns to Make Sorted Link Link
953. Verifying an Alien Dictionary Link Link
961. N-Repeated Element in Size 2N Array Link Link
965. Univalued Binary Tree Link Link
976. Largest Perimeter Triangle Link Link
977. Squares of a Sorted Array Link Link
989. Add to Array-Form of Integer Link Link
993. Cousins in Binary Tree Link Link
997. Find the Town Judge Link Link
1002. Find Common Characters Link Link
1005. Maximize Sum Of Array After K Negations Link Link
1009. Complement of Base 10 Integer Link Link
1018. Binary Prefix Divisible By 5 Link Link
1021. Remove Outermost Parentheses Link Link
1022. Sum of Root To Leaf Binary Numbers Link Link
1025. Divisor Game Link Link
1046. Last Stone Weight Link Link
1047. Remove All Adjacent Duplicates In String Link Link
1051. Height Checker Link Link
1071. Greatest Common Divisor of Strings Link Link
1078. Occurrences After Bigram Link Link
1089. Duplicate Zeros Link Link
1103. Distribute Candies to People Link Link
1108. Defanging an IP Address Link Link
1114. Print in Order Link Link
1137. N-th Tribonacci Number Link Link
1154. Day of the Year Link Link
1160. Find Words That Can Be Formed by Characters Link Link
1184. Distance Between Bus Stops Link Link
1185. Day of the Week Link Link
1189. Maximum Number of Balloons Link Link
1200. Minimum Absolute Difference Link Link
1207. Unique Number of Occurrences Link Link
1217. Minimum Cost to Move Chips to The Same Position Link Link
1221. Split a String in Balanced Strings Link Link
1232. Check If It Is a Straight Line Link Link
1252. Cells with Odd Values in a Matrix Link Link
1266. Minimum Time Visiting All Points Link Link
1275. Find Winner on a Tic Tac Toe Game Link Link
1281. Subtract the Product and Sum of Digits of an Integer Link Link
1287. Element Appearing More Than 25% In Sorted Array Link Link
1290. Convert Binary Number in a Linked List to Integer Link Link
1295. Find Numbers with Even Number of Digits Link Link
1299. Replace Elements with Greatest Element on Right Side Link Link
1304. Find N Unique Integers Sum up to Zero Link Link
1309. Decrypt String from Alphabet to Integer Mapping Link Link
1313. Decompress Run-Length Encoded List Link Link
1317. Convert Integer to the Sum of Two No-Zero Integers Link Link
1323. Maximum 69 Number Link Link
1332. Remove Palindromic Subsequences Link Link
1337. The K Weakest Rows in a Matrix Link Link
1342. Number of Steps to Reduce a Number to Zero Link Link
1346. Check If N and Its Double Exist Link Link
1351. Count Negative Numbers in a Sorted Matrix Link Link
1356. Sort Integers by The Number of 1 Bits Link Link
1360. Number of Days Between Two Dates Link Link
1365. How Many Numbers Are Smaller Than the Current Number Link Link
1370. Increasing Decreasing String Link Link
1374. Generate a String With Characters That Have Odd Counts Link Link
1379. Find a Corresponding Node of a Binary Tree in a Clone of That Tree Link Link
1385. Find the Distance Value Between Two Arrays Link Link
1389. Create Target Array in the Given Order Link Link
1399. Count Largest Group Link Link
1403. Minimum Subsequence in Non-Increasing Order Link Link
1408. String Matching in an Array Link Link
1413. Minimum Value to Get Positive Step by Step Sum Link Link
1417. Reformat The String Link Link
1991. Find the Middle Index in Array Link Link
1431. Kids With the Greatest Number of Candies Link Link
1436. Destination City Link Link
1437. Check If All 1's Are at Least Length K Places Away Link Link
1446. Consecutive Characters Link Link
1450. Number of Students Doing Homework at a Given Time Link Link
1455. Check If a Word Occurs As a Prefix of Any Word in a Sentence Link Link
1460. Make Two Arrays Equal by Reversing Sub-arrays Link Link
1464. Maximum Product of Two Elements in an Array Link Link
1470. Shuffle the Array Link Link
1475. Final Prices With a Special Discount in a Shop Link Link
1480. Running Sum of 1d Array Link Link
1486. XOR Operation in an Array Link Link
1491. Average Salary Excluding the Minimum and Maximum Salary Link Link
1496. Path Crossing Link Link
1502. Can Make Arithmetic Progression From Sequence Link Link
1507. Reformat Date Link Link
1512. Number of Good Pairs Link Link
1518. Water Bottles Link Link
1523. Count Odd Numbers in an Interval Range Link Link
1528. Shuffle String Link Link
1534. Count Good Triplets Link Link
1539. Kth Missing Positive Number Link Link
1544. Make The String Great Link Link
1550. Three Consecutive Odds Link Link
1556. Thousand Separator Link Link
1566. Detect Pattern of Length M Repeated K or More Times Link Link
1572. Matrix Diagonal Sum Link Link
1576. Replace All ?'s to Avoid Consecutive Repeating Characters Link Link
1582. Special Positions in a Binary Matrix Link Link
1588. Sum of All Odd Length Subarrays Link Link
1592. Rearrange Spaces Between Words Link Link
1598. Crawler Log Folder Link Link
1603. Design Parking System Link Link
1608. Special Array With X Elements Greater Than or Equal X Link Link
1614. Maximum Nesting Depth of the Parentheses Link Link
1619. Mean of Array After Removing Some Elements Link Link
1624. Largest Substring Between Two Equal Characters Link Link
1629. Slowest Key Link Link
1636. Sort Array by Increasing Frequency Link Link
1646. Get Maximum in Generated Array Link Link
1652. Defuse the Bomb Link Link
1662. Check If Two String Arrays are Equivalent Link Link
1668. Maximum Repeating Substring Link Link
1672. Richest Customer Wealth Link Link
1678. Goal Parser Interpretation Link Link
1684. Count the Number of Consistent Strings Link Link
1688. Count of Matches in Tournament Link Link
1694. Reformat Phone Number Link Link
1700. Number of Students Unable to Eat Lunch Link Link
1704. Determine if String Halves Are Alike Link Link
1710. Maximum Units on a Truck Link Link
1716. Calculate Money in Leetcode Bank Link Link
1720. Decode XORed Array Link Link
1725. Number Of Rectangles That Can Form The Largest Square Link Link
1732. Find the Highest Altitude Link Link
1736. Latest Time by Replacing Hidden Digits Link Link
1748. Sum of Unique Elements Link Link
1752. Check if Array Is Sorted and Rotated Link Link
1768. Merge Strings Alternately Link Link
1773. Count Items Matching a Rule Link Link
1779. Find Nearest Point That Has the Same X or Y Coordinate Link Link
1784. Check if Binary String Has at Most One Segment of Ones Link Link
1790. Check if One String Swap Can Make Strings Equal Link Link
1791. Find Center of Star Graph Link Link
1796. Second Largest Digit in a String Link Link
1800. Maximum Ascending Subarray Sum Link Link
1805. Number of Different Integers in a String Link Link
1812. Determine Color of a Chessboard Square Link Link
1816. Truncate Sentence Link Link
1822. Sign of the Product of an Array Link Link
1827. Minimum Operations to Make the Array Increasing Link Link
1832. Check if the Sentence Is Pangram Link Link
1837. Sum of Digits in Base K Link Link
1844. Replace All Digits with Characters Link Link
1848. Minimum Distance to the Target Element Link Link
1859. Sorting the Sentence Link Link
1863. Sum of All Subset XOR Totals Link Link
1869. Longer Contiguous Segments of Ones than Zeros Link Link
1876. Substrings of Size Three with Distinct Characters Link Link
1880. Check if Word Equals Summation of Two Words Link Link
1886. Determine Whether Matrix Can Be Obtained By Rotation Link Link
1893. Check if All the Integers in a Range Are Covered Link Link
1897. Redistribute Characters to Make All Strings Equal Link Link
1903. Largest Odd Number in String Link Link
1909. Remove One Element to Make the Array Strictly Increasing Link Link
1913. Maximum Product Difference Between Two Pairs Link Link
1920. Build Array from Permutation Link Link
1925. Count Square Sum Triples Link Link
1929. Concatenation of Array Link Link
1935. Maximum Number of Words You Can Type Link Link
1941. Check if All Characters Have Equal Number of Occurrences Link Link
1952. Three Divisors Link Link
1957. Delete Characters to Make Fancy String Link Link
1961. Check If String Is a Prefix of Array Link Link
1967. Number of Strings That Appear as Substrings in Word Link Link
1971. Find if Path Exists in Graph Link Link
1974. Minimum Time to Type Word Using Special Typewriter Link Link
1979. Find Greatest Common Divisor of Array Link Link
1984. Minimum Difference Between Highest and Lowest of K Scores Link Link
1991. Find the Middle Index in Array Link Link
1995. Count Special Quadruplets Link Link
2000. Reverse Prefix of Word Link Link
2006. Count Number of Pairs With Absolute Difference K Link Link
2011. Final Value of Variable After Performing Operations Link Link
2016. Maximum Difference Between Increasing Elements Link Link
2022. Convert 1D Array Into 2D Array Link Link
2027. Minimum Moves to Convert String Link Link
2032. Two Out of Three Link Link
2037. Minimum Number of Moves to Seat Everyone Link Link
2042. Check if Numbers Are Ascending in a Sentence Link Link
2047. Number of Valid Words in a Sentence Link Link
2053. Kth Distinct String in an Array Link Link
2057. Smallest Index With Equal Value Link Link
2062. Count Vowel Substrings of a String Link Link
2068. Check Whether Two Strings are Almost Equivalent Link Link
2073. Time Needed to Buy Tickets Link Link
2078. Two Furthest Houses With Different Colors Link Link
2085. Count Common Words With One Occurrence Link Link
2089. Find Target Indices After Sorting Array Link Link
2094. Finding 3-Digit Even Numbers Link Link
2099. Find Subsequence of Length K With the Largest Sum Link Link
2103. Rings and Rods Link Link
2108. Find First Palindromic String in the Array Link Link
2114. Maximum Number of Words Found in Sentences Link Link
2119. A Number After a Double Reversal Link Link
2124. Check if All A's Appears Before All B's Link Link
2129. Capitalize the Title Link Link
2133. Check if Every Row and Column Contains All Numbers Link Link
2138. Divide a String Into Groups of Size k Link Link
2148. Count Elements With Strictly Smaller and Greater Elements Link Link
2154. Keep Multiplying Found Values by Two Link Link
2160. Minimum Sum of Four Digit Number After Splitting Digits Link Link
2164. Sort Even and Odd Indices Independently Link Link
2169. Count Operations to Obtain Zero Link Link
2176. Count Equal and Divisible Pairs in an Array Link Link
2180. Count Integers With Even Digit Sum Link Link
2185. Counting Words With a Given Prefix Link Link
2190. Most Frequent Number Following Key In an Array Link Link
2194. Cells in a Range on an Excel Sheet Link Link
2206. Divide Array Into Equal Pairs Link Link
2210. Count Hills and Valleys in an Array Link Link
2215. Find the Difference of Two Arrays Link Link
2220. Minimum Bit Flips to Convert Number Link Link
2231. Largest Number After Digit Swaps by Parity Link Link
2235. Add Two Integers Link Link
2236. Root Equals Sum of Children Link Link
2239. Find Closest Number to Zero Link Link
2243. Calculate Digit Sum of a String Link Link
2248. Intersection of Multiple Arrays Link Link
2255. Count Prefixes of a Given String Link Link
2259. Remove Digit From Number to Maximize Result Link Link
2264. Largest 3-Same-Digit Number in String Link Link
2278. Percentage of Letter in String Link Link
2283. Check if Number Has Equal Digit Count and Digit Value Link Link
2287. Rearrange Characters to Make Target String Link Link
2293. Min Max Game Link Link
2299. Strong Password Checker II Link Link
2303. Calculate Amount Paid in Taxes Link Link
2309. Greatest English Letter in Upper and Lower Case Link Link
2315. Count Asterisks Link Link
2319. Check if Matrix Is X-Matrix Link Link
2325. Decode the Message Link Link
2331. Evaluate Boolean Binary Tree Link Link
2341. Maximum Number of Pairs in Array Link Link
2347. Best Poker Hand Link Link
2351. First Letter to Appear Twice Link Link
2335. Minimum Amount of Time to Fill Cups Link Link
2357. Make Array Zero by Subtracting Equal Amounts Link Link
2367. Number of Arithmetic Triplets Link Link
2363. Merge Similar Items Link Link
2373. Largest Local Values in a Matrix Link Link
2379. Minimum Recolors to Get K Consecutive Black Blocks Link Link
2383. Minimum Hours of Training to Win a Competition Link Link
2389. Longest Subsequence With Limited Sum Link Link
2395. Find Subarrays With Equal Sum Link Link
2399. Check Distances Between Same Letters Link Link
2404. Most Frequent Even Element Link Link
2413. Smallest Even Multiple Link Link
2418. Sort the People Link Link
2423. Remove Letter To Equalize Frequency Link Link
2427. Number of Common Factors Link Link
2432. The Employee That Worked on the Longest Task Link Link
2441. Largest Positive Integer That Exists With Its Negative Link Link
2446. Determine if Two Events Have Conflict Link Link
2455. Average Value of Even Numbers That Are Divisible by Three Link Link
2460. Apply Operations to an Array Link Link
2469. Convert the Temperature Link Link
2475. Number of Unequal Triplets in Array Link Link
2481. Minimum Cuts to Divide a Circle Link Link
2485. Find the Pivot Integer Link Link
2490. Circular Sentence Link Link
2496. Maximum Value of a String in an Array Link Link
2500. Delete Greatest Value in Each Row Link Link
2506. Count Pairs Of Similar Strings Link Link
2511. Maximum Enemy Forts That Can Be Captured Link Link
2515. Shortest Distance to Target String in a Circular Array Link Link
2520. Count the Digits That Divide a Number Link Link
2525. Categorize Box According to Criteria Link Link
2529. Maximum Count of Positive Integer and Negative Integer Link Link
2535. Difference Between Element Sum and Digit Sum of an Array Link Link
2540. Minimum Common Value Link Link
2544. Alternating Digit Sum Link Link
2549. Count Distinct Numbers on Board Link Link

Medium

Name Link to LeetCode Link to solution
2. Add Two Numbers Link Link
3. Longest Substring Without Repeating Characters Link Link
5. Longest Palindromic Substring Link Link
7. Reverse Integer Link Link
8. String to Integer (atoi) Link Link
11. Container With Most Water Link Link
12. Integer to Roman Link Link
15. 3Sum Link Link
16. 3Sum Closest Link Link
17. Letter Combinations of a Phone Number Link Link
19. Remove Nth Node From End of List Link Link
22. Generate Parentheses Link Link
24. Swap Nodes in Pairs Link Link
28. Find the Index of the First Occurrence in a String Link Link
29. Divide Two Integers Link Link
33. Search in Rotated Sorted Array Link Link
34. Find First and Last Position of Element in Sorted Array Link Link
36. Valid Sudoku Link Link
38. Count and Say Link Link
39. Combination Sum Link Link
43. Multiply Strings Link Link
46. Permutations Link Link
48. Rotate Image Link Link
49. Group Anagrams Link Link
53. Maximum Subarray Link Link
54. Spiral Matrix Link Link
55. Jump Game Link Link
56. Merge Intervals Link Link
57. Insert Interval Link Link
59. Spiral Matrix II Link Link
61. Rotate List Link Link
62. Unique Paths Link Link
71. Simplify Path Link Link
74. Search a 2D Matrix Link Link
75. Sort Colors Link Link
78. Subsets Link Link
82. Remove Duplicates from Sorted List II Link Link
86. Partition List Link Link
92. Reverse Linked List II Link Link
95. Unique Binary Search Trees II Link Link
96. Unique Binary Search Trees Link Link
98. Validate Binary Search Tree Link Link
99. Recover Binary Search Tree Link Link
102. Binary Tree Level Order Traversal Link Link
103. Binary Tree Zigzag Level Order Traversal Link Link
105. Construct Binary Tree from Preorder and Inorder Traversal Link Link
106. Construct Binary Tree from Inorder and Postorder Traversal Link Link
107. Binary Tree Level Order Traversal II Link Link
109. Convert Sorted List to Binary Search Tree Link Link
113. Path Sum II Link Link
114. Flatten Binary Tree to Linked List Link Link
116. Populating Next Right Pointers in Each Node Link Link
117. Populating Next Right Pointers in Each Node II Link Link
120. Triangle Link Link
128. Longest Consecutive Sequence Link Link
129. Sum Root to Leaf Numbers Link Link
133. Clone Graph Link Link
134. Gas Station Link Link
138. Copy List with Random Pointer Link Link
142. Linked List Cycle II Link Link
143. Reorder List Link Link
146. LRU Cache Link Link
147. Insertion Sort List Link Link
148. Sort List Link Link
150. Evaluate Reverse Polish Notation Link Link
151. Reverse Words in a String Link Link
155. Min Stack Link Link
165. Compare Version Numbers Link Link
167. Two Sum II - Input Array Is Sorted Link Link
173. Binary Search Tree Iterator Link Link
179. Largest Number Link Link
187. Repeated DNA Sequences Link Link
189. Rotate Array Link Link
199. Binary Tree Right Side View Link Link
200. Number of Islands Link Link
204. Count Primes Link Link
208. Implement Trie (Prefix Tree) Link Link
209. Minimum Size Subarray Sum Link Link
215. Kth Largest Element in an Array Link Link
222. Count Complete Tree Nodes Link Link
227. Basic Calculator II Link Link
230. Kth Smallest Element in a BST Link Link
235. Lowest Common Ancestor of a Binary Search Tree Link Link
236. Lowest Common Ancestor of a Binary Tree Link Link
237. Delete Node in a Linked List Link Link
238. Product of Array Except Self Link Link
240. Search a 2D Matrix II Link Link
284. Peeking Iterator Link Link
287. Find the Duplicate Number Link Link
299. Bulls and Cows Link Link
300. Longest Increasing Subsequence Link Link
304. Range Sum Query 2D - Immutable Link Link
316. Remove Duplicate Letters Link Link
318. Maximum Product of Word Lengths Link Link
328. Odd Even Linked List Link Link
331. Verify Preorder Serialization of a Binary Tree Link Link
334. Increasing Triplet Subsequence Link Link
341. Flatten Nested List Iterator Link Link
347. Top K Frequent Elements Link Link
371. Sum of Two Integers Link Link
377. Combination Sum IV Link Link
378. Kth Smallest Element in a Sorted Matrix Link Link
380. Insert Delete GetRandom O(1) Link Link
382. Linked List Random Node Link Link
388. Longest Absolute File Path Link Link
394. Decode String Link Link
398. Random Pick Index Link Link
402. Remove K Digits Link Link
417. Pacific Atlantic Water Flow Link Link
424. Longest Repeating Character Replacement Link Link
429. N-ary Tree Level Order Traversal Link Link
435. Non-overlapping Intervals Link Link
438. Find All Anagrams in a String Link Link
442. Find All Duplicates in an Array Link Link
443. String Compression Link Link
445. Add Two Numbers II Link Link
449. Serialize and Deserialize BST Link Link
450. Delete Node in a BST Link Link
451. Sort Characters By Frequency Link Link
453. Minimum Moves to Equal Array Elements Link Link
456. 132 Pattern Link Link
462. Minimum Moves to Equal Array Elements II Link Link
468. Validate IP Address Link Link
474. Ones and Zeroes Link Link
503. Next Greater Element II Link Link
508. Most Frequent Subtree Sum Link Link
513. Find Bottom Left Tree Value Link Link
515. Find Largest Value in Each Tree Row Link Link
516. Longest Palindromic Subsequence Link Link
523. Continuous Subarray Sum Link Link
524. Longest Word in Dictionary through Deleting Link Link
535. Encode and Decode TinyURL Link Link
538. Convert BST to Greater Tree Link Link
556. Next Greater Element III Link Link
560. Subarray Sum Equals K Link Link
581. Shortest Unsorted Continuous Subarray Link Link
609. Find Duplicate File in System Link Link
621. Task Scheduler Link Link
622. Design Circular Queue Link Link
623. Add One Row to Tree Link Link
641. Design Circular Deque Link Link
647. Palindromic Substrings Link Link
648. Replace Words Link Link
652. Find Duplicate Subtrees Link Link
654. Maximum Binary Tree Link Link
659. Split Array into Consecutive Subsequences Link Link
662. Maximum Width of Binary Tree Link Link
669. Trim a Binary Search Tree Link Link
677. Map Sum Pairs Link Link
678. Valid Parenthesis String Link Link
687. Longest Univalue Path Link Link
692. Top K Frequent Words Link Link
701. Insert into a Binary Search Tree Link Link
707. Design Linked List Link Link
720. Longest Word in Dictionary Link Link
725. Split Linked List in Parts Link Link
729. My Calendar I Link Link
735. Asteroid Collision Link Link
739. Daily Temperatures Link Link
763. Partition Labels Link Link
784. Letter Case Permutation Link Link
797. All Paths From Source to Target Link Link
814. Binary Tree Pruning Link Link
817. Linked List Components Link Link
823. Binary Trees With Factors Link Link
841. Keys and Rooms Link Link
852. Peak Index in a Mountain Array Link Link
856. Score of Parentheses Link Link
858. Mirror Reflection Link Link
863. All Nodes Distance K in Binary Tree Link Link
865. Smallest Subtree with all the Deepest Nodes Link Link
869. Reordered Power of 2 Link Link
880. Decoded String at Index Link Link
889. Construct Binary Tree from Preorder and Postorder Traversal Link Link
890. Find and Replace Pattern Link Link
894. All Possible Full Binary Trees Link Link
901. Online Stock Span Link Link
910. Smallest Range II Link Link
912. Sort an Array Link Link
916. Word Subsets Link Link
919. Complete Binary Tree Inserter Link Link
921. Minimum Add to Make Parentheses Valid Link Link
937. Reorder Data in Log Files Link Link
946. Validate Stack Sequences Link Link
950. Reveal Cards In Increasing Order Link Link
951. Flip Equivalent Binary Trees Link Link
958. Check Completeness of a Binary Tree Link Link
967. Numbers With Same Consecutive Differences Link Link
973. K Closest Points to Origin Link Link
979. Distribute Coins in Binary Tree Link Link
981. Time Based Key-Value Store Link Link
985. Sum of Even Numbers After Queries Link Link
988. Smallest String Starting From Leaf Link Link
998. Maximum Binary Tree II Link Link
1008. Construct Binary Search Tree from Preorder Traversal Link Link
1019. Next Greater Node In Linked List Link Link
1023. Camelcase Matching Link Link
1026. Maximum Difference Between Node and Ancestor Link Link
1038. Binary Search Tree to Greater Sum Tree Link Link
1043. Partition Array for Maximum Sum Link Link
1079. Letter Tile Possibilities Link Link
1081. Smallest Subsequence of Distinct Characters Link Link
1110. Delete Nodes And Return Forest Link Link
1111. Maximum Nesting Depth of Two Valid Parentheses Strings Link Link
1115. Print FooBar Alternately Link Link
1123. Lowest Common Ancestor of Deepest Leaves Link Link
1161. Maximum Level Sum of a Binary Tree Link Link
1171. Remove Zero Sum Consecutive Nodes from Linked List Link Link
1209. Remove All Adjacent Duplicates in String II Link Link
1247. Minimum Swaps to Make Strings Equal Link Link
1248. Count Number of Nice Subarrays Link Link
1249. Minimum Remove to Make Valid Parentheses Link Link
1261. Find Elements in a Contaminated Binary Tree Link Link
1288. Remove Covered Intervals Link Link
1302. Deepest Leaves Sum Link Link
1305. All Elements in Two Binary Search Trees Link Link
1310. XOR Queries of a Subarray Link Link
1315. Sum of Nodes with Even-Valued Grandparent Link Link
1325. Delete Leaves With a Given Value Link Link
1329. Sort the Matrix Diagonally Link Link
1338. Reduce Array Size to The Half Link Link
1339. Maximum Product of Splitted Binary Tree Link Link
1343. Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold Link Link
1347. Minimum Number of Steps to Make Two Strings Anagram Link Link
1358. Number of Substrings Containing All Three Characters Link Link
1367. Linked List in Binary Tree Link Link
1376. Time Needed to Inform All Employees Link Link
1381. Design a Stack With Increment Operation Link Link
1382. Balance a Binary Search Tree Link Link
1387. Sort Integers by The Power Value Link Link
1395. Count Number of Teams Link Link
1396. Design Underground System Link Link
1433. Check If a String Can Break Another String Link Link
1442. Count Triplets That Can Form Two Arrays of Equal XOR Link Link
1448. Count Good Nodes in Binary Tree Link Link
1457. Pseudo-Palindromic Paths in a Binary Tree Link Link
1461. Check If a String Contains All Binary Codes of Size K Link Link
1472. Design Browser History Link Link
1481. Least Number of Unique Integers after K Removals Link Link
1492. The kth Factor of n Link Link
1504. Count Submatrices With All Ones Link Link
1525. Number of Good Ways to Split a String Link Link
1529. Minimum Suffix Flips Link Link
1530. Number of Good Leaf Nodes Pairs Link Link
1557. Minimum Number of Vertices to Reach All Nodes Link Link
1609. Even Odd Tree Link Link
1630. Arithmetic Subarrays Link Link
1641. Count Sorted Vowel Strings Link Link
1669. Merge In Between Linked Lists Link Link
1670. Design Front Middle Back Queue Link Link
1679. Max Number of K-Sum Pairs Link Link
1685. Sum of Absolute Differences in a Sorted Array Link Link
1706. Where Will the Ball Fall Link Link
1721. Swapping Nodes in a Linked List Link Link
1770. Maximum Score from Performing Multiplication Operations Link Link
1780. Check if Number is a Sum of Powers of Three Link Link
1797. Design Authentication Manager Link Link
1814. Count Nice Pairs in an Array Link Link
1823. Find the Winner of the Circular Game Link Link
1829. Maximum XOR for Each Query Link Link
1834. Single-Threaded CPU Link Link
1845. Seat Reservation Manager Link Link
1877. Minimize Maximum Pair Sum in Array Link Link
1910. Remove All Occurrences of a Substring Link Link
1985. Find the Kth Largest Integer in the Array Link Link
1996. The Number of Weak Characters in the Game Link Link
2007. Find Original Array From Doubled Array Link Link
2023. Number of Pairs of Strings With Concatenation Equal to Target Link Link
2058. Find the Minimum and Maximum Number of Nodes Between Critical Points Link Link
2063. Vowels of All Substrings Link Link
2074. Reverse Nodes in Even Length Groups Link Link
2091. Removing Minimum and Maximum From Array Link Link
2095. Delete the Middle Node of a Linked List Link Link
2096. Step-By-Step Directions From a Binary Tree Node to Another Link Link
2109. Adding Spaces to a String Link Link
2121. Intervals Between Identical Elements Link Link
2125. Number of Laser Beams in a Bank Link Link
2130. Maximum Twin Sum of a Linked List Link Link
2131. Longest Palindrome by Concatenating Two Letter Words Link Link
2149. Rearrange Array Elements by Sign Link Link
2150. Find All Lonely Numbers in the Array Link Link
2161. Partition Array According to Given Pivot Link Link
2165. Smallest Value of the Rearranged Number Link Link
2177. Find Three Consecutive Integers That Sum to a Given Number Link Link
2181. Merge Nodes in Between Zeros Link Link
2196. Create Binary Tree From Descriptions Link Link
2221. Find Triangular Sum of an Array Link Link
2225. Find Players With Zero or One Losses Link Link
2233. Maximum Product After K Increments Link Link
2265. Count Nodes Equal to Average of Subtree Link Link
2266. Count Number of Texts Link Link
2295. Replace Elements in an Array Link Link
2326. Spiral Matrix IV Link Link
2375. Construct Smallest Number From DI String Link Link
2390. Removing Stars From a String Link Link
2415. Reverse Odd Levels of Binary Tree Link Link
2487. Remove Nodes From Linked List Link Link

Hard

Name Link to LeetCode Link to solution
4. Median of Two Sorted Arrays Link Link
10. Regular Expression Matching Link Link
23. Merge k Sorted Lists Link Link
25. Reverse Nodes in k-Group Link Link
30. Substring with Concatenation of All Words Link Link
32. Longest Valid Parentheses Link Link
41. First Missing Positive Link Link
115. Distinct Subsequences Link Link
126. Word Ladder II Link Link
233. Number of Digit One Link Link
239. Sliding Window Maximum Link Link
297. Serialize and Deserialize Binary Tree Link Link
336. Palindrome Pairs Link Link
363. Max Sum of Rectangle No Larger Than K Link Link
458. Poor Pigs Link Link
871. Minimum Number of Refueling Stops Link Link
895. Maximum Frequency Stack Link Link
936. Stamping The Sequence Link Link
968. Binary Tree Cameras Link Link
1106. Parsing A Boolean Expression Link Link
1220. Count Vowels Permutation Link Link
1944. Number of Visible People in a Queue Link Link