LeetCode_Solution

LeetCode: https://leetcode.com/problemset/all/

#	Title	Difficulty	Colab Code
1	Two Sum	Easy
2	Add Two Numbers	Medium
3	Longest Substring Without Repeating Characters	Medium
4	Median of Two Sorted Arrays	Hard
5	Longest Palindromic Substring	Medium
7	Reverse Integer	Easy
8	String to Integer (atoi)	Medium
9	Palindrome Number	Easy
10	Regular Expression Matching	Hard
11	Container With Most Water	Medium
12	Integer to Roman	Medium
13	Roman to Integer	Easy
14	Longest Common Prefix	Easy
15	3Sum	Medium
16	3Sum Closest	Medium
17	Letter Combinations of a Phone Number	Medium
18	4Sum	Medium
19	Remove Nth Node From End of List	Medium
20	Valid Parentheses	Easy
21	Merge Two Sorted Lists	Easy
22	Generate Parentheses	Medium
23	Merge k Sorted Lists	Hard
24	Swap Nodes in Pairs	Medium
25	Reverse Nodes in k-Group	Hard
26	Remove Duplicates from Sorted Array	Easy
27	Remove Element	Easy
28	Implement strStr()	Easy
29	Divide Two Integers	Medium
30	Substring with Concatenation of All Words	Hard
31	Next Permutation	Medium
32	Longest Valid Parentheses	Hard
33	Search in Rotated Sorted Array	Medium
34	Find First and Last Position of Element in Sorted Array	Medium
35	Search Insert Position	Easy
36	Valid Sudoku	Medium
37	Sudoku Solver	Hard
38	Count and Say	Medium
39	Combination Sum	Medium
40	Combination Sum II	Medium
41	First Missing Positive	Hard
42	Trapping Rain Water	Hard
43	Multiply Strings	Medium
44	Wildcard Matching	Hard
45	Jump Game II	Medium
46	Permutations	Medium
47	Permutations II	Medium
48	Rotate Image	Medium
49	Group Anagrams	Medium
50	Pow(x, n)	Medium
51	N-Queens	Hard
53	Maximum Subarray	Easy
54	Spiral Matrix	Medium
55	Jump Game	Medium
56	Merge Intervals	Medium
57	Insert Interval	Medium
61	Rotate List	Medium
62	Unique Paths	Medium
63	Unique Paths II	Medium
64	Minimum Path Sum	Medium
66	Plus One	Easy
67	Add Binary	Easy
68	Text Justification	Hard
69	Sqrt(x)	Easy
70	Climbing Stairs	Easy
71	Simplify Path	Medium
72	Edit Distance	Hard
73	Set Matrix Zeroes	Medium
74	Search a 2D Matrix	Medium
75	Sort Colors	Medium
76	Minimum Window Substring	Hard
77	Combinations	Medium
78	Subsets	Medium
79	Word Search	Medium
81	Search in Rotated Sorted Array II	Medium
82	Remove Duplicates from Sorted List II	Medium
84	Largest Rectangle in Histogram	Hard
85	Maximal Rectangle	Hard
86	Partition List	Medium
88	Merge Sorted Array	Easy
91	Decode Ways	Medium
92	Reverse Linked List II	Medium
93	Restore IP Addresses	Medium
94	Binary Tree Inorder Traversal	Easy
96	Unique Binary Search Trees	Medium
98	Validate Binary Search Tree	Medium
99	Recover Binary Search Tree	Medium
100	Same Tree	Easy
101	Symmetric Tree	Easy
102	Binary Tree Level Order Traversal	Medium
103	Binary Tree Zigzag Level Order Traversal	Medium
104	Maximum Depth of Binary Tree	Easy
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium
109	Convert Sorted List to Binary Search Tree	Medium
110	Balanced Binary Tree	Easy
111	Minimum Depth of Binary Tree	Easy
112	Path Sum	Easy
114	Flatten Binary Tree to Linked List	Medium
116	Populating Next Right Pointers in Each Node	Medium
117	Populating Next Right Pointers in Each Node II	Medium
120	Triangle	Medium
121	Best Time to Buy and Sell Stock	Easy
122	Best Time to Buy and Sell Stock II	Easy
123	Best Time to Buy and Sell Stock III	Hard
124	Binary Tree Maximum Path Sum	Hard
125	Valid Palindrome	Easy
126	Word Ladder II	Hard
127	Word Ladder	Hard
128	Longest Consecutive Sequence	Medium
130	Surrounded Regions	Medium
133	Clone Graph	Medium
134	Gas Station	Medium
135	Candy	Hard
136	Single Number	Easy
137	Single Number II	Medium
138	Copy List with Random Pointer	Medium
139	Word Break	Medium
140	Word Break II	Hard
141	Linked List Cycle	Easy
142	Linked List Cycle II	Medium
143	Reorder List	Medium
144	Binary Tree Preorder Traversal	Easy
145	Binary Tree Postorder Traversal	Easy
146	LRU Cache	Medium
149	Max Points on a Line	Hard
150	Evaluate Reverse Polish Notation	Medium
152	Maximum Product Subarray	Medium
153	Find Minimum in Rotated Sorted Array	Medium
154	Find Minimum in Rotated Sorted Array II	Hard
155	Min Stack	Easy
159	Longest Substring with At Most Two Distinct Characters	Medium
160	Intersection of Two Linked Lists	Easy
162	Find Peak Element	Medium
165	Compare Version Numbers	Medium
167	Two Sum II - Input array is sorted	Easy
169	Majority Element	Easy
173	Binary Search Tree Iterator	Medium
174	Dungeon Game	Hard
179	Largest Number	Medium
188	Best Time to Buy and Sell Stock IV	Hard
189	Rotate Array	Medium
198	House Robber	Medium
199	Binary Tree Right Side View	Medium
200	Number of Islands	Medium
201	Bitwise AND of Numbers Range	Medium
202	Happy Number	Easy
203	Remove Linked List Elements	Easy
204	Count Primes	Easy
205	Isomorphic Strings	Easy
206	Reverse Linked List	Easy
207	Course Schedule	Medium
208	Implement Trie (Prefix Tree)	Medium
209	Minimum Size Subarray Sum	Medium
210	Course Schedule II	Medium
211	Design Add and Search Words Data Structure	Medium
212	Word Search II	Hard
215	Kth Largest Element in an Array	Medium
217	Contains Duplicate	Easy
218	The Skyline Problem	Hard
219	Contains Duplicate II	Easy
221	Maximal Square	Medium
222	Count Complete Tree Nodes	Medium
224	Basic Calculator	Hard
225	Implement Stack using Queues	Easy
226	Invert Binary Tree	Easy
227	Basic Calculator II	Medium
229	Majority Element II	Medium
230	Kth Smallest Element in a BST	Medium
232	Implement Queue using Stacks	Easy
234	Palindrome Linked List	Easy
235	Lowest Common Ancestor of a Binary Search Tree	Easy
236	Lowest Common Ancestor of a Binary Tree	Medium
238	Product of Array Except Self	Medium
239	Sliding Window Maximum	Hard
240	Search a 2D Matrix II	Medium
242	Valid Anagram	Easy
244	Shortest Word Distance II	Medium
252	Meeting Rooms	Easy
253	Meeting Rooms II	Medium
258	Add Digits	Easy
261	Graph Valid Tree	Medium
268	Missing Number	Easy
269	Alien Dictionary	Hard
273	Integer to English Words	Hard
277	Find the Celebrity	Medium
278	First Bad Version	Easy
279	Perfect Squares	Medium
283	Move Zeroes	Easy
284	Peeking Iterator	Medium
285	Inorder Successor in BST	Medium
286	Walls and Gates	Medium
287	Find the Duplicate Number	Medium
289	Game of Life	Medium
295	Find Median from Data Stream	Hard
296	Best Meeting Point	Hard
297	Serialize and Deserialize Binary Tree	Hard
300	Longest Increasing Subsequence	Medium
301	Remove Invalid Parentheses	Hard
305	Number of Islands II	Hard
312	Burst Balloons	Hard
314	Binary Tree Vertical Order Traversal	Medium
315	Count of Smaller Numbers After Self	Hard
316	Remove Duplicate Letters	Medium
322	Coin Change	Medium
323	Number of Connected Components in an Undirected Graph	Medium
324	Wiggle Sort II	Medium
328	Odd Even Linked List	Medium
329	Longest Increasing Path in a Matrix	Hard
332	Reconstruct Itinerary	Medium
334	Increasing Triplet Subsequence	Medium
337	House Robber III	Medium
338	Counting Bits	Easy
339	Nested List Weight Sum	Medium
341	Flatten Nested List Iterator	Medium
344	Reverse String	Easy
345	Reverse Vowels of a String	Easy
346	Moving Average from Data Stream	Easy
347	Top K Frequent Elements	Medium
348	Design Tic-Tac-Toe	Medium
349	Intersection of Two Arrays	Easy
350	Intersection of Two Arrays II	Easy
353	Design Snake Game	Medium
354	Russian Doll Envelopes	Hard
355	Design Twitter	Medium
362	Design Hit Counter	Medium
366	Find Leaves of Binary Tree	Medium
368	Largest Divisible Subset	Medium
373	Find K Pairs with Smallest Sums	Medium
377	Combination Sum IV	Medium
378	Kth Smallest Element in a Sorted Matrix	Medium
380	Insert Delete GetRandom O(1)	Medium
381	Insert Delete GetRandom O(1) - Duplicates allowed	Hard
383	Ransom Note	Easy
387	First Unique Character in a String	Easy
388	Longest Absolute File Path	Medium
394	Decode String	Medium
395	Longest Substring with At Least K Repeating Characters	Medium
399	Evaluate Division	Medium
400	Nth Digit	Medium
402	Remove K Digits	Medium
403	Frog Jump	Hard
407	Trapping Rain Water II	Hard
410	Split Array Largest Sum	Hard
412	Fizz Buzz	Easy
415	Add Strings	Easy
416	Partition Equal Subset Sum	Medium
417	Pacific Atlantic Water Flow	Medium
424	Longest Repeating Character Replacement	Medium
432	All O`one Data Structure	Hard
435	Non-overlapping Intervals	Medium
437	Path Sum III	Medium
438	Find All Anagrams in a String	Medium
442	Find All Duplicates in an Array	Medium
443	String Compression	Medium
445	Add Two Numbers II	Medium
448	Find All Numbers Disappeared in an Array	Easy
449	Serialize and Deserialize BST	Medium
454	4Sum II	Medium
456	132 Pattern	Medium
460	LFU Cache	Hard
471	Encode String with Shortest Length	Hard
472	Concatenated Words	Hard
490	The Maze	Medium
493	Reverse Pairs	Hard
494	Target Sum	Medium
496	Next Greater Element I	Easy
498	Diagonal Traverse	Medium
503	Next Greater Element II	Medium
516	Longest Palindromic Subsequence	Medium
518	Coin Change 2	Medium
523	Continuous Subarray Sum	Medium
525	Contiguous Array	Medium
535	Encode and Decode TinyURL	Medium
540	Single Element in a Sorted Array	Medium
542	01 Matrix	Medium
543	Diameter of Binary Tree	Easy
545	Boundary of Binary Tree	Medium
547	Number of Provinces	Medium
1730	Shortest Path to Get Food	Medium
557	Reverse Words in a String III	Easy
560	Subarray Sum Equals K	Medium
564	Find the Closest Palindrome	Hard
567	Permutation in String	Medium
572	Subtree of Another Tree	Easy
576	Out of Boundary Paths	Medium
581	Shortest Unsorted Continuous Subarray	Medium
588	Design In-Memory File System	Hard
609	Find Duplicate File in System	Medium
617	Merge Two Binary Trees	Easy
621	Task Scheduler	Medium
628	Maximum Product of Three Numbers	Easy
632	Smallest Range Covering Elements from K Lists	Hard
635	Design Log Storage System	Medium
636	Exclusive Time of Functions	Medium
642	Design Search Autocomplete System	Hard
646	Maximum Length of Pair Chain	Medium
647	Palindromic Substrings	Medium
650	2 Keys Keyboard	Medium
652	Find Duplicate Subtrees	Medium
657	Robot Return to Origin	Easy
658	Find K Closest Elements	Medium
674	Longest Continuous Increasing Subsequence	Easy
675	Cut Off Trees for Golf Event	Hard
678	Valid Parenthesis String	Medium
682	Baseball Game	Easy
684	Redundant Connection	Medium
685	Redundant Connection II	Hard
688	Knight Probability in Chessboard	Medium
692	Top K Frequent Words	Medium
694	Number of Distinct Islands	Medium
695	Max Area of Island	Medium
713	Subarray Product Less Than K	Medium
715	Range Module	Hard
716	Max Stack	Easy
718	Maximum Length of Repeated Subarray	Medium
721	Accounts Merge	Medium
726	Number of Atoms	Hard
727	Minimum Window Subsequence	Hard
733	Flood Fill	Easy
735	Asteroid Collision	Medium
739	Daily Temperatures	Medium
709	To Lower Case	Easy
743	Network Delay Time	Medium
746	Min Cost Climbing Stairs	Easy
752	Open the Lock	Medium
426	Convert Binary Search Tree to Sorted Doubly Linked List	Medium
759	Employee Free Time	Hard
429	N-ary Tree Level Order Traversal	Medium
428	Serialize and Deserialize N-ary Tree	Hard
763	Partition Labels	Medium
590	N-ary Tree Postorder Traversal	Easy
767	Reorganize String	Medium
771	Jewels and Stones	Easy
772	Basic Calculator III	Hard
703	Kth Largest Element in a Stream	Easy
775	Global and Local Inversions	Medium
783	Minimum Distance Between BST Nodes	Easy
785	Is Graph Bipartite?	Medium
787	Cheapest Flights Within K Stops	Medium
790	Domino and Tromino Tiling	Medium
792	Number of Matching Subsequences	Medium
794	Valid Tic-Tac-Toe State	Medium
796	Rotate String	Easy
797	All Paths From Source to Target	Medium
706	Design HashMap	Easy
814	Binary Tree Pruning	Medium
815	Bus Routes	Hard
819	Most Common Word	Easy
826	Most Profit Assigning Work	Medium
829	Consecutive Numbers Sum	Hard
641	Design Circular Deque	Medium
622	Design Circular Queue	Medium
489	Robot Room Cleaner	Hard
836	Rectangle Overlap	Easy
841	Keys and Rooms	Medium
844	Backspace String Compare	Easy
849	Maximize Distance to Closest Person	Medium
853	Car Fleet	Medium
856	Score of Parentheses	Medium
862	Shortest Subarray with Sum at Least K	Hard
863	All Nodes Distance K in Binary Tree	Medium
872	Leaf-Similar Trees	Easy
875	Koko Eating Bananas	Medium
876	Middle of the Linked List	Easy
528	Random Pick with Weight	Medium
887	Super Egg Drop	Hard
889	Construct Binary Tree from Preorder and Postorder Traversal	Medium
895	Maximum Frequency Stack	Hard
898	Bitwise ORs of Subarrays	Medium
901	Online Stock Span	Medium
909	Snakes and Ladders	Medium
912	Sort an Array	Medium
931	Minimum Falling Path Sum	Medium
937	Reorder Data in Log Files	Easy
939	Minimum Area Rectangle	Medium
953	Verifying an Alien Dictionary	Easy
957	Prison Cells After N Days	Medium
970	Powerful Integers	Medium
509	Fibonacci Number	Easy
973	K Closest Points to Origin	Medium
979	Distribute Coins in Binary Tree	Medium
980	Unique Paths III	Hard
981	Time Based Key-Value Store	Medium
986	Interval List Intersections	Medium
987	Vertical Order Traversal of a Binary Tree	Hard
992	Subarrays with K Different Integers	Hard
993	Cousins in Binary Tree	Easy
994	Rotting Oranges	Medium
1000	Minimum Cost to Merge Stones	Hard
1002	Find Common Characters	Easy
1008	Construct Binary Search Tree from Preorder Traversal	Medium
1057	Campus Bikes	Medium
1010	Pairs of Songs With Total Durations Divisible by 60	Medium
1011	Capacity To Ship Packages Within D Days	Medium
1060	Missing Element in Sorted Array	Medium
1087	Brace Expansion	Medium
1024	Video Stitching	Medium
1099	Two Sum Less Than K	Easy
1120	Maximum Average Subtree	Medium
1026	Maximum Difference Between Node and Ancestor	Medium
1031	Maximum Sum of Two Non-Overlapping Subarrays	Medium
1135	Connecting Cities With Minimum Cost	Medium
1152	Analyze User Website Visit Pattern	Medium
1160	Find Words That Can Be Formed by Characters	Easy
1041	Robot Bounded In Circle	Medium
1043	Partition Array for Maximum Sum	Medium
1044	Longest Duplicate Substring	Hard
1166	Design File System	Medium
1167	Minimum Cost to Connect Sticks	Medium
1047	Remove All Adjacent Duplicates In String	Easy
1180	Count Substrings with Only One Distinct Letter	Easy
1197	Minimum Knight Moves	Medium
1071	Greatest Common Divisor of Strings	Easy
1229	Meeting Scheduler	Medium
1091	Shortest Path in Binary Matrix	Medium
1244	Design A Leaderboard	Medium
1105	Filling Bookcase Shelves	Medium
1106	Parsing A Boolean Expression	Hard
1110	Delete Nodes And Return Forest	Medium
1122	Relative Sort Array	Easy
1138	Alphabet Board Path	Medium
1313	Decompress Run-Length Encoded List	Easy
1314	Matrix Block Sum	Medium
1143	Longest Common Subsequence	Medium
1328	Break a Palindrome	Medium
1329	Sort the Matrix Diagonally	Medium
1302	Deepest Leaves Sum	Medium
1156	Swap For Longest Repeated Character Substring	Medium
1155	Number of Dice Rolls With Target Sum	Medium
1236	Web Crawler	Medium
1169	Invalid Transactions	Medium
1360	Number of Days Between Two Dates	Easy
1382	Balance a Binary Search Tree	Medium
1483	Kth Ancestor of a Tree Node	Hard
1190	Reverse Substrings Between Each Pair of Parentheses	Medium
1192	Critical Connections in a Network	Hard
1405	Longest Happy String	Medium
1209	Remove All Adjacent Duplicates in String II	Medium
1217	Minimum Cost to Move Chips to The Same Position	Easy
1220	Count Vowels Permutation	Hard
1222	Queens That Can Attack the King	Medium
1233	Remove Sub-Folders from the Filesystem	Medium
1235	Maximum Profit in Job Scheduling	Hard
1429	First Unique Number	Medium
1249	Minimum Remove to Make Valid Parentheses	Medium
1254	Number of Closed Islands	Medium
1255	Maximum Score Words Formed by Letters	Hard
1268	Search Suggestions System	Medium
1275	Find Winner on a Tic Tac Toe Game	Easy
1277	Count Square Submatrices with All Ones	Medium
1293	Shortest Path in a Grid with Obstacles Elimination	Hard
1312	Minimum Insertion Steps to Make a String Palindrome	Hard
1344	Angle Between Hands of a Clock	Medium
1345	Jump Game IV	Hard
1335	Minimum Difficulty of a Job Schedule	Hard
1351	Count Negative Numbers in a Sorted Matrix	Easy
1365	How Many Numbers Are Smaller Than the Current Number	Easy
1386	Cinema Seat Allocation	Medium
1376	Time Needed to Inform All Employees	Medium
1395	Count Number of Teams	Medium
1431	Kids With the Greatest Number of Candies	Easy
1448	Count Good Nodes in Binary Tree	Medium
1465	Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts	Medium
1491	Average Salary Excluding the Minimum and Maximum Salary	Easy
1480	Running Sum of 1d Array	Easy
1481	Least Number of Unique Integers after K Removals	Medium
1487	Making File Names Unique	Medium
1496	Path Crossing	Easy
1539	Kth Missing Positive Number	Easy
1559	Detect Cycles in 2D Grid	Hard
1547	Minimum Cost to Cut a Stick	Hard
1603	Design Parking System	Easy
1600	Throne Inheritance	Medium
1597	Build Binary Expression Tree From Infix Expression	Hard
1636	Sort Array by Increasing Frequency	Easy
1629	Slowest Key	Easy
1641	Count Sorted Vowel Strings	Medium
1670	Design Front Middle Back Queue	Medium
1628	Design an Expression Tree With Evaluate Function	Medium
1647	Minimum Deletions to Make Character Frequencies Unique	Medium
1648	Sell Diminishing-Valued Colored Balls	Medium
1650	Lowest Common Ancestor of a Binary Tree III	Medium
1673	Find the Most Competitive Subsequence	Medium
1710	Maximum Units on a Truck	Easy
1751	Maximum Number of Events That Can Be Attended II	Hard
1740	Find Distance in a Binary Tree	Medium
1761	Minimum Degree of a Connected Trio in a Graph	Hard
1770	Maximum Score from Performing Multiplication Operations	Medium
1799	Maximize Score After N Operations	Hard
1869	Longer Contiguous Segments of Ones than Zeros	Easy
175	Combine Two Tables	Easy
176	Second Highest Salary	Easy
180	Consecutive Numbers	Medium
181	Employees Earning More Than Their Managers	Easy
184	Department Highest Salary	Medium
185	Department Top Three Salaries	Hard
196	Delete Duplicate Emails	Easy
262	Trips and Users	Hard
579	Find Cumulative Salary of an Employee	Hard
615	Average Salary: Departments VS Company	Hard
626	Exchange Seats	Medium
1164	Product Price at a Given Date	Medium
1270	All People Report to the Given Manager	Medium
1479	Sales by Day of the Week	Hard
1511	Customer Order Frequency	Easy
1596	The Most Frequently Ordered Products for Each Customer	Medium
1783	Grand Slam Titles	Medium