LeetCode All In One

English | 简体中文

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Provide all my solutions and explanations in Chinese for all the Leetcode coding problems.

Same as this: LeetCode All in One 题目讲解汇总(持续更新中...)

Note: All explanations are written in Github Issues, please do not create any new issue in this project since the problem index should be consistent with the issue index, thanks!

('$' means the problem is locked on Leetcode, '*' means the problem is related to Database, '#' means the problem is related to Shell.)

#	Title	Solution	Difficulty
880	Decoded String at Index	23.00%	Medium
879	Profitable Schemes	36.20%	Hard
878	Nth Magical Number	25.40%	Hard
877	Stone Game	61.10%	Medium
876	Middle of the Linked List	63.80%	Easy
875	Koko Eating Bananas	45.90%	Medium
874	Walking Robot Simulation	31.70%	Easy
873	Length of Longest Fibonacci Subsequence	46.00%	Medium
872	Leaf-Similar Trees	63.10%	Easy
871	Minimum Number of Refueling Stops	28.70%	Hard
870	Advantage Shuffle	42.20%	Medium
869	Reordered Power of 2	50.60%	Medium
868	Binary Gap	59.30%	Easy
867	Transpose Matrix	63.90%	Easy
866	Prime Palindrome	20.00%	Medium
865	Smallest Subtree with all the Deepest Nodes	55.40%	Medium
864	Shortest Path to Get All Keys	35.70%	Hard
863	All Nodes Distance K in Binary Tree	46.80%	Medium
862	Shortest Subarray with Sum at Least K	22.00%	Hard
861	Score After Flipping Matrix	69.30%	Medium
860	Lemonade Change	50.20%	Easy
859	Buddy Strings	27.60%	Easy
858	Mirror Reflection	52.00%	Medium
857	Minimum Cost to Hire K Workers	47.30%	Hard
856	Score of Parentheses	55.90%	Medium
855	Exam Room	38.10%	Medium
854	K-Similar Strings	33.20%	Hard
853	Car Fleet	39.30%	Medium
852	Peak Index in a Mountain Array	68.50%	Easy
851	Loud and Rich	47.40%	Medium
850	Rectangle Area II	44.00%	Hard
849	Maximize Distance to Closest Person	40.40%	Easy
848	Shifting Letters	39.90%	Medium
847	Shortest Path Visiting All Nodes	45.90%	Hard
846	Hand of Straights	48.60%	Medium
845	Longest Mountain in Array	34.00%	Medium
844	Backspace String Compare	45.50%	Easy
843	Guess the Word	42.60%	Hard
842	Split Array into Fibonacci Sequence	34.60%	Medium
841	Keys and Rooms	59.70%	Medium
840	Magic Squares In Grid	35.10%	Easy
839	Similar String Groups	33.50%	Hard
838	Push Dominoes	42.80%	Medium
837	New 21 Game	29.50%	Medium
836	Rectangle Overlap	45.50%	Easy
835	Image Overlap	50.30%	Medium
834	Sum of Distances in Tree	38.10%	Hard
833	Find And Replace in String	44.50%	Medium
832	Flipping an Image	71.30%	Easy
831	Masking Personal Information	41.50%	Medium
830	Positions of Large Groups	47.40%	Easy
829	Consecutive Numbers Sum	32.10%	Hard
828	Unique Letter String	38.10%	Hard
827	Making A Large Island	42.10%	Hard
826	Most Profit Assigning Work	34.70%	Medium
825	Friends Of Appropriate Ages	35.00%	Medium
824	Goat Latin	56.70%	Easy
823	Binary Trees With Factors	31.50%	Medium
822	Card Flipping Game	39.70%	Medium
821	Shortest Distance to a Character	62.60%	Easy
820	Short Encoding of Words	46.00%	Medium
819	Most Common Word	41.50%	Easy
818	Race Car	34.00%	Hard
817	Linked List Components	51.90%	Medium
816	Ambiguous Coordinates	42.40%	Medium
815	Bus Routes	36.10%	Hard
814	Binary Tree Pruning	68.30%	Medium
813	Largest Sum of Averages	42.40%	Medium
812	Largest Triangle Area	53.80%	Easy
811	Subdomain Visit Count	61.50%	Easy
810	Chalkboard XOR Game	41.90%	Hard
809	Expressive Words	39.50%	Medium
808	Soup Servings	33.60%	Medium
807	Max Increase to Keep City Skyline	79.60%	Medium
806	Number of Lines To Write String	62.10%	Easy
805	Split Array With Same Average	21.00%	Hard
804	Unique Morse Code Words	71.30%	Easy
803	Bricks Falling When Hit	22.90%	Hard
802	Find Eventual Safe States	39.20%	Medium
801	Minimum Swaps To Make Sequences Increasing	31.00%	Medium
800	Similar RGB Color $	54.50%	Easy
799	Champagne Tower	29.90%	Medium
798	Smallest Rotation with Highest Score	34.30%	Hard
797	All Paths From Source to Target	67.40%	Medium
796	Rotate String	49.60%	Easy
795	Number of Subarrays with Bounded Maximum	41.60%	Medium
794	Valid Tic-Tac-Toe State	27.80%	Medium
793	Preimage Size of Factorial Zeroes Function	40.80%	Hard
792	Number of Matching Subsequences	37.30%	Medium
791	Custom Sort String	59.40%	Medium
790	Domino and Tromino Tiling	32.80%	Medium
789	Escape The Ghosts	51.00%	Medium
788	Rotated Digits	51.00%	Easy
787	Cheapest Flights Within K Stops	29.90%	Medium
786	K-th Smallest Prime Fraction	32.50%	Hard
785	Is Graph Bipartite	38.50%	Medium
784	Letter Case Permutation	53.00%	Easy
783	Minimum Distance Between BST Nodes	47.80%	Easy
782	Transform to Chessboard	37.50%	Hard
781	Rabbits in Forest	49.80%	Medium
780	Reaching Points	23.90%	Hard
779	K-th Symbol in Grammar	37.30%	Medium
778	Swim in Rising Water	44.60%	Hard
777	Swap Adjacent in LR String	28.90%	Medium
776	Split BST $	49.90%	Medium
775	Global and Local Inversions	33.60%	Medium
774	Minimize Max Distance to Gas Station $	32.80%	Hard
773	Sliding Puzzle	46.50%	Hard
772	Basic Calculator III $	40.10%	Hard
771	Jewels and Stones	81.90%	Easy
770	Basic Calculator IV	42.10%	Hard
769	Max Chunks To Make Sorted	48.00%	Medium
768	Max Chunks To Make Sorted II	43.20%	Hard
767	Reorganize String	36.50%	Medium
766	Toeplitz Matrix	57.90%	Easy
765	Couples Holding Hands	48.50%	Hard
764	Largest Plus Sign	39.20%	Medium
763	Partition Labels	64.10%	Medium
762	Prime Number of Set Bits in Binary Representation	55.00%	Easy
761	Special Binary String	41.00%	Hard
760	Find Anagram Mappings $	75.60%	Easy
759	Employee Free Time $	51.90%	Hard
758	Bold Words in String $	37.90%	Easy
757	Set Intersection Size At Least Two	34.60%	Hard
756	Pyramid Transition Matrix	45.50%	Medium
755	Pour Water $	34.00%	Medium
754	Reach a Number	26.10%	Medium
753	Cracking the Safe	39.70%	Hard
752	Open the Lock	38.20%	Medium
751	IP to CIDR $	54.80%	Easy
750	Number Of Corner Rectangles $	51.00%	Medium
749	Contain Virus	39.60%	Hard
748	Shortest Completing Word	53.50%	Medium
747	Largest Number At Least Twice of Others	42.60%	Easy
746	Min Cost Climbing Stairs	43.60%	Easy
745	Prefix and Suffix Search	24.50%	Hard
744	Find Smallest Letter Greater Than Target	45.30%	Easy
743	Network Delay Time	34.30%	Medium
742	Closest Leaf in a Binary Tree $	33.20%	Medium
741	Cherry Pickup	22.50%	Hard
740	Delete and Earn	42.60%	Medium
739	Daily Temperatures	53.50%	Medium
738	Monotone Increasing Digits	41.80%	Medium
737	Sentence Similarity II $	41.20%	Medium
736	Parse Lisp Expression	42.00%	Hard
735	Asteroid Collision	37.60%	Medium
734	Sentence Similarity $	38.60%	Easy
733	Flood Fill	49.30%	Easy
732	My Calendar III	51.30%	Hard
731	My Calendar II	35.00%	Medium
730	Count Different Palindromic Subsequences	32.40%	Hard
729	My Calendar I	40.10%	Medium
728	Self Dividing Numbers	68.50%	Easy
727	Minimum Window Subsequence	30.10%	Hard
726	Number of Atoms	45.00%	Hard
725	Split Linked List in Parts	50.00%	Medium
724	Find Pivot Index	41.00%	Easy
723	Candy Crush $	56.10%	Medium
722	Remove Comments	26.30%	Medium
721	Accounts Merge	29.60%	Medium
720	Longest Word in Dictionary	40.60%	Easy
719	Find K-th Smallest Pair Distance	26.10%	Hard
718	Maximum Length of Repeated Subarray	39.90%	Medium
717	1-bit and 2-bit Characters	50.90%	Easy
716	Max Stack $	35.50%	Hard
715	Range Module	31.00%	Hard
714	Best Time to Buy and Sell Stock with Transaction Fee	41.60%	Medium
713	Subarray Product Less Than K	32.90%	Medium
712	Minimum ASCII Delete Sum for Two Strings	50.90%	Medium
711	Number of Distinct Islands II $	39.40%	Hard
710	Random Pick with Blacklist	29.80%	Hard
709	To Lower Case	74.50%	Easy
708	Insert into a Cyclic Sorted List $	25.50%	Medium
707	Design Linked List	19.10%	Easy
706	Design HashMap	49.10%	Easy
705	Design HashSet	43.60%	Easy
704	Binary Search	40.10%	Easy
703	Kth Largest Element in a Stream	39.60%	Easy
702	Search in a Sorted Array of Unknown Size	43.00%	Medium
701	Insert into a Binary Search Tree	67.90%	Medium
700	Search in a Binary Search Tree	62.70%	Easy
699	Falling Squares	36.80%	Hard
698	Partition to K Equal Sum Subsets	35.60%	Medium
697	Degree of an Array	47.90%	Easy
696	Count Binary Substrings	51.90%	Easy
695	Max Area of Island	53.30%	Easy
694	Number of Distinct Islands $	43.90%	Medium
693	Binary Number with Alternating Bits	54.20%	Easy
692	Top K Frequent Words	41.70%	Medium
691	Stickers to Spell Word	32.30%	Hard
690	Employee Importance	53.60%	Easy
689	Maximum Sum of 3 Non-Overlapping Subarrays	41.70%	Hard
688	Knight Probability in Chessboard	38.90%	Medium
687	Longest Univalue Path	32.90%	Easy
686	Repeated String Match	31.70%	Easy
685	Redundant Connection II	28.40%	Hard
684	Redundant Connection	37.40%	Medium
683	K Empty Slots	37.00%	Hard
682	Baseball Game	58.60%	Easy
681	Next Closest Time $	43.00%	Medium
680	Valid Palindrome II	31.10%	Easy
679	24 Game	38.30%	Hard
678	Valid Parenthesis String	28.30%	Medium
677	Map Sum Pairs	53.80%	Medium
676	Implement Magic Dictionary	50.70%	Medium
675	Cut Off Trees for Golf Event	27.20%	Hard
674	Longest Continuous Increasing Subsequence	43.20%	Easy
673	Number of Longest Increasing Subsequence	30.80%	Medium
672	Bulb Switcher II	47.60%	Medium
671	Second Minimum Node In a Binary Tree	42.30%	Easy
670	Maximum Swap	38.40%	Medium
669	Trim a Binary Search Tree	58.70%	Easy
668	Kth Smallest Number in Multiplication Table	36.30%	Hard
667	Beautiful Arrangement II	51.50%	Medium
666	Path Sum IV $	48.90%	Medium
665	Non-decreasing Array	21.20%	Easy
664	Strange Printer	31.10%	Hard
663	Equal Tree Partition $	36.70%	Medium
662	Maximum Width of Binary Tree	37.00%	Medium
661	Image Smoother	46.60%	Easy
660	Remove 9 $	46.10%	Hard
659	Split Array into Consecutive Subsequences	39.40%	Medium
658	Find K Closest Elements	36.30%	Medium
657	Judge Route Circle	69.30%	Easy
656	Coin Path $	24.60%	Hard
655	Print Binary Tree	50.80%	Medium
654	Maximum Binary Tree	70.80%	Medium
653	Two Sum IV - Input is a BST	50.60%	Easy
652	Find Duplicate Subtrees	33.20%	Medium
651	4 Keys Keyboard $	46.70%	Medium
650	2 Keys Keyboard	42.70%	Medium
649	Dota2 Senate	35.60%	Medium
648	Replace Words	48.40%	Medium
647	Palindromic Substrings	55.70%	Medium
646	Maximum Length of Pair Chain	47.40%	Medium
645	Set Mismatch	40.40%	Easy
644	Maximum Average Subarray II $	20.30%	Hard
643	Maximum Average Subarray I	38.40%	Easy
642	Design Search Autocomplete System $	29.40%	Hard
641	Design Circular Deque	48.00%	Medium
640	Solve the Equation	39.00%	Medium
639	Decode Ways II	22.80%	Hard
638	Shopping Offers	41.50%	Medium
637	Average of Levels in Binary Tree	55.60%	Easy
636	Exclusive Time of Functions	40.30%	Medium
635	Design Log Storage System $	47.70%	Medium
634	Find the Derangement of An Array $	32.70%	Medium
633	Sum of Square Numbers	31.60%	Easy
632	Smallest Range	42.80%	Hard
631	Design Excel Sum Formula $	25.60%	Hard
630	Course Schedule III	20.50%	Medium
629	K Inverse Pairs Array	23.90%	Hard
628	Maximum Product of Three Numbers	45.40%	Easy
627	Swap Salary	67.40%	Easy
626	Exchange Seats	49.60%	Medium
625	Minimum Factorization	29.50%	Medium
624	Maximum Distance in Arrays $	32.70%	Easy
623	Add One Row to Tree	48.70%	Medium
622	Design Circular Queue	36.60%	Medium
621	Task Scheduler	41.40%	Medium
620	Not Boring Movies	59.80%	Easy
619	Biggest Single Number $	36.60%	Easy
618	Students Report By Geography $	40.40%	Hard
617	Merge Two Binary Trees	69.60%	Easy
616	Add Bold Tag in String $	37.30%	Medium
615	Average Salary: Departments VS Company $	33.00%	Hard
614	Second Degree Follower $	22.70%	Medium
613	Shortest Distance in a Line $	70.60%	Easy
612	Shortest Distance in a Plane $	51.00%	Medium
611	Valid Triangle Number	38.90%	Medium
610	Triangle Judgement $	59.10%	Easy
609	Find Duplicate File in System	52.50%	Medium
608	Tree Node $	54.60%	Medium
607	Sales Person $	51.10%	Easy
606	Construct String from Binary Tree	51.80%	Easy
605	Can Place Flowers	30.00%	Easy
604	Design Compressed String Iterator $	31.60%	Easy
603	Consecutive Available Seats $	54.50%	Easy
602	Friend Requests II: Who Has the Most Friends $	42.50%	Medium
601	Human Traffic of Stadium	33.80%	Hard
600	Non-negative Integers without Consecutive Ones	27.40%	Hard
599	Minimum Index Sum of Two Lists	48.00%	Easy
598	Range Addition II	48.30%	Easy
597	Friend Requests I: Overall Acceptance Rate $	38.40%	Easy
596	Classes More Than 5 Students	33.40%	Easy
595	Big Countries	72.00%	Easy
594	Longest Harmonious Subsequence	40.00%	Easy
593	Valid Square	39.20%	Medium
592	Fraction Addition and Subtraction	47.00%	Medium
591	Tag Validator	26.40%	Hard
590	N-ary Tree Postorder Traversal	63.00%	Easy
589	N-ary Tree Preorder Traversal	63.10%	Easy
588	Design In-Memory File System $	32.40%	Hard
587	Erect the Fence	29.90%	Hard
586	Customer Placing the Largest Number of Orders $	62.50%	Easy
585	Investments in 2016 $	44.60%	Medium
584	Find Customer Referee $	63.60%	Easy
583	Delete Operation for Two Strings	44.00%	Medium
582	Kill Process $	47.70%	Medium
581	Shortest Unsorted Continuous Subarray	30.10%	Easy
580	Count Student Number in Departments $	40.00%	Medium
579	Find Cumulative Salary of an Employee $	30.90%	Hard
578	Get Highest Answer Rate Question $	33.10%	Medium
577	Employee Bonus $	53.80%	Easy
576	Out of Boundary Paths	33.10%	Medium
575	Distribute Candies	59.50%	Easy
574	Winning Candidate $	34.50%	Medium
573	Squirrel Simulation $	51.00%	Medium
572	Subtree of Another Tree	41.00%	Easy
571	Find Median Given Frequency of Numbers $	44.90%	Hard
570	Managers with at Least 5 Direct Reports $	59.00%	Medium
569	Median Employee Salary $	41.60%	Hard
568	Maximum Vacation Days $	39.90%	Hard
567	Permutation in String	36.30%	Medium
566	Reshape the Matrix	59.80%	Easy
565	Array Nesting	50.00%	Medium
564	Find the Closest Palindrome	16.60%	Hard
563	Binary Tree Tilt	47.00%	Easy
562	Longest Line of Consecutive One in Matrix $	38.80%	Medium
561	Array Partition I	69.80%	Easy
560	Subarray Sum Equals K	41.80%	Medium
559	Maximum Depth of N-ary Tree	62.10%	Easy
558	Quad Tree Intersection	36.40%	Easy
557	Reverse Words in a String III	61.20%	Easy
556	Next Greater Element III	27.70%	Medium
555	Split Concatenated Strings $	30.00%	Medium
554	Brick Wall	42.70%	Medium
553	Optimal Division	55.20%	Medium
552	Student Attendance Record II	28.50%	Hard
551	Student Attendance Record I	43.90%	Easy
549	Binary Tree Longest Consecutive Sequence II $	38.10%	Medium
548	Split Array with Equal Sum $	30.80%	Medium
547	Friend Circles	49.00%	Medium
546	Remove Boxes	29.60%	Hard
545	Boundary of Binary Tree $	29.10%	Medium
544	Output Contest Matches $	73.20%	Medium
543	Diameter of Binary Tree	42.70%	Easy
542	01 Matrix	32.50%	Medium
541	Reverse String II	44.40%	Easy
540	Single Element in a Sorted Array	55.90%	Medium
539	Minimum Time Difference	44.70%	Medium
538	Convert BST to Greater Tree	52.70%	Medium
537	Complex Number Multiplication	65.90%	Medium
536	Construct Binary Tree from String $	36.30%	Medium
535	Encode and Decode TinyURL	76.10%	Medium
534	Design TinyURL	N/A	Medium
533	Lonely Pixel II $	38.90%	Medium
532	K-diff Pairs in an Array	27.20%	Easy
531	Lonely Pixel I $	50.20%	Medium
530	Minimum Absolute Difference in BST	48.00%	Easy
529	Minesweeper	52.00%	Medium
528	Random Pick with Weight	41.80%	Medium
527	Word Abbreviation $	33.90%	Hard
526	Beautiful Arrangement	53.50%	Medium
525	Contiguous Array	34.40%	Medium
524	Longest Word in Dictionary through Deleting	40.20%	Medium
523	Continuous Subarray Sum	21.3	Medium
522	Longest Uncommon Subsequence II	28.10%	Medium
521	Longest Uncommon Subsequence I	50.70%	Easy
520	Detect Capital	54.20%	Easy
519	Random Flip Matrix	32.20%	Medium
518	Coin Change 2	33.20%	Medium
517	Super Washing Machines	34.60%	Hard
516	Longest Palindromic Subsequence	42.00%	Medium
515	Find Largest Value in Each Tree Row	52.70%	Medium
514	Freedom Trail	27.20%	Hard
513	Find Bottom Left Tree Value	55.60%	Medium
510	Inorder Successor in BST II $	56.20%	Medium
509	Fibonacci Number	66.40%	Easy
508	Most Frequent Subtree Sum	52.00%	Medium
507	Perfect Number	32.70%	Easy
506	Relative Ranks	48.50%	Easy
505	The Maze II	34.80%	Medium
504	Base 7	46.40%	Easy
503	Next Greater Element II	46.20%	Medium
502	IPO	32.40%	Hard
501	Find Mode in Binary Search Tree	39.40%	Easy
500	Keyboard Row	60.20%	Easy
499	The Maze III	32.00%	Hard
498	Diagonal Traverse	46.20%	Medium
497	Random Point in Non-overlapping Rectangles	33.20%	Medium
496	Next Greater Element I	58.80%	Easy
495	Teemo Attacking	51.90%	Medium
494	Target Sum	44.40%	Medium
493	Reverse Pairs	17.10%	Hard
492	Construct the Rectangle	49.70%	Easy
491	Increasing Subsequences	39.30%	Medium
490	The Maze	42.80%	Medium
489	Robot Room Cleaner	57.10%	Hard
488	Zuma Game	38.00%	Hard
487	Max Consecutive Ones II $	42.70%	Medium
486	Predict the Winner	43.60%	Medium
485	Max Consecutive Ones	55.30%	Easy
484	Find Permutation $	50.50%	Medium
483	Smallest Good Base	30.60%	Hard
482	License Key Formatting	41.20%	Medium
481	Magical String	46.20%	Medium
480	Sliding Window Median	31.00%	Hard
479	Largest Palindrome Product	23.90%	Easy
478	Generate Random Point in a Circle	33.80%	Medium
477	Total Hamming Distance	44.10%	Medium
476	Number Complement	61.20%	Easy
475	Heaters	30.20%	Easy
474	Ones and Zeroes	34.90%	Medium
473	Matchsticks to Square	31.80%	Medium
472	Concatenated Words	29.20%	Hard
471	Encode String with Shortest Length $	43.50%	Hard
470	Implement Rand10() Using Rand7()	43.00%	Medium
469	Convex Polygon $	27.20%	Medium
468	Validate IP Address	22.10%	Medium
467	Unique Substrings in Wraparound String	29.90%	Medium
466	Count The Repetitions	24.20%	Hard
465	Optimal Account Balancing $	29.20%	Hard
464	Can I Win	22.20%	Medium
463	Island Perimeter	56.70%	Easy
462	Minimum Moves to Equal Array Elements II	50.90%	Medium
461	Hamming Distance	73.20%	Easy
460	LFU Cache	18.30%	Hard
459	Repeated Substring Pattern	39.70%	Easy
458	Poor Pigs	40.70%	Easy
457	Circular Array Loop	20.60%	Medium
456	132 Pattern	28.00%	Medium
455	Assign Cookies	48.10%	Easy
454	4Sum II	42.80%	Medium
453	Minimum Moves to Equal Array Elements	46.30%	Easy
452	Minimum Number of Arrows to Burst Balloons	42.10%	Medium
451	Sort Characters By Frequency	50.90%	Medium
450	Delete Node in a BST	34.50%	Medium
449	Serialize and Deserialize BST	41.20%	Medium
448	Find All Numbers Disappeared in an Array	58.30%	Easy
447	Number of Boomerangs	42.20%	Easy
446	Arithmetic Slices II - Subsequence	22.30%	Hard
445	Add Two Numbers II	45.40%	Medium
444	Sequence Reconstruction $	20.50%	Medium
443	String Compression	35.80%	Easy
442	Find All Duplicates in an Array	46.40%	Medium
441	Arranging Coins	36.20%	Easy
440	K-th Smallest in Lexicographical Order	21.50%	Hard
439	Ternary Expression Parser $	49.40%	Medium
438	Find All Anagrams in a String	33.50%	Easy
437	Path Sum III	38.60%	Easy
436	Find Right Interval	42.30%	Medium
435	Non-overlapping Intervals	39.80%	Medium
434	Number of Segments in a String	38.40%	Easy
433	Minimum Genetic Mutation	33.50%	Medium
432	All O`one Data Structure	28.30%	Hard
431	Encode N-ary Tree to Binary Tree $	53.70%	Hard
430	Flatten a Multilevel Doubly Linked List	36.20%	Medium
429	N-ary Tree Level Order Traversal	55.80%	Easy
428	Serialize and Deserialize N-ary Tree $	48.10%	Hard
427	Construct Quad Tree	49.20%	Easy
426	Convert Binary Search Tree to Sorted Doubly Linked List	43.30%	Medium
425	Word Squares $	40.10%	Hard
424	Longest Repeating Character Replacement	38.10%	Medium
423	Reconstruct Original Digits from English	40.80%	Medium
422	Valid Word Square $	36.40%	Easy
421	Maximum XOR of Two Numbers in an Array	36.40%	Medium
420	Strong Password Checker	22.10%	Hard
419	Battleships in a Board	59.30%	Medium
418	Sentence Screen Fitting $	25.10%	Medium
417	Pacific Atlantic Water Flow	31.10%	Medium
416	Partition Equal Subset Sum	36.80%	Medium
415	Add Strings	41.50%	Easy
414	Third Maximum Number	26.50%	Easy
413	Arithmetic Slices	53.50%	Medium
412	Fizz Buzz	57.50%	Easy
411	Minimum Unique Word Abbreviation $	25.60%	Hard
410	Split Array Largest Sum	25.00%	Hard
409	Longest Palindrome	44.90%	Easy
408	Valid Word Abbreviation $	26.20%	Easy
407	Trapping Rain Water II	33.10%	Hard
406	Queue Reconstruction by Height	54.10%	Medium
405	Convert a Number to Hexadecimal	41.80%	Easy
404	Sum of Left Leaves	46.20%	Easy
403	Frog Jump	31.70%	Hard
402	Remove K Digits	25.90%	Medium
401	Binary Watch	43.00%	Easy
400	Nth Digit	30.70%	Easy
399	Evaluate Division	34.60%	Medium
398	Random Pick Index	30.40%	Medium
397	Integer Replacement	25.90%	Easy
396	Rotate Function	28.40%	Easy
395	Longest Substring with At Least K Repeating Characters	32.50%	Medium
394	Decode String	38.60%	Medium
393	UTF-8 Validation	33.00%	Medium
392	Is Subsequence	44.10%	Medium
391	Perfect Rectangle	13.30%	Hard
390	Elimination Game	12.50%	Medium
389	Find the Difference	49.90%	Easy
388	Longest Absolute File Path	28.30%	Medium
387	First Unique Character in a String	43.10%	Easy
386	Lexicographical Numbers	31.00%	Medium
385	Mini Parser	26.90%	Medium
384	Shuffle an Array	45.50%	Medium
383	Ransom Note	44.60%	Easy
382	Linked List Random Node	48.60%	Medium
381	Insert Delete GetRandom O(1) - Duplicates allowed	30.90%	Hard
380	Insert Delete GetRandom O(1)	33.80%	Medium
379	Design Phone Directory $	25.80%	Medium
378	Kth Smallest Element in a Sorted Matrix	40.20%	Medium
377	Combination Sum IV	37.50%	Medium
376	Wiggle Subsequence	35.80%	Medium
375	Guess Number Higher or Lower II	28.30%	Medium
374	Guess Number Higher or Lower	31.70%	Easy
373	Find K Pairs with Smallest Sums	25.50%	Medium
372	Super Pow	30.10%	Medium
371	Sum of Two Integers	54.00%	Easy
370	Range Addition $	49.90%	Medium
369	Plus One Linked List $	50.10%	Medium
368	Largest Divisible Subset	32.00%	Medium
367	Valid Perfect Square	36.60%	Medium
366	Find Leaves of Binary Tree $	53.60%	Medium
365	Water and Jug Problem	20.10%	Medium
364	Nested List Weight Sum II $	47.20%	Medium
363	Max Sum of Rectangle No Larger Than K	27.00%	Hard
362	Design Hit Counter $	48.30%	Medium
361	Bomb Enemy $	32.60%	Medium
360	Sort Transformed Array $	40.80%	Medium
359	Logger Rate Limiter $	56.00%	Easy
358	Rearrange String k Distance Apart $	26.90%	Hard
357	Count Numbers with Unique Digits	42.50%	Medium
356	Line Reflection $	28.70%	Medium
355	Design Twitter	22.20%	Medium
354	Russian Doll Envelopes	27.10%	Hard
353	Design Snake Game $	19.80%	Medium
352	Data Stream as Disjoint Intervals	34.40%	Hard
351	Android Unlock Patterns $	32.00%	Medium
350	Intersection of Two Arrays II	41.50%	Easy
349	Intersection of Two Arrays	47.80%	Easy
348	Design Tic-Tac-Toe $	45.60%	Medium
347	Top K Frequent Elements	44.50%	Medium
346	Moving Average from Data Stream $	69.20%	Easy
345	Reverse Vowels of a String	35.30%	Easy
344	Reverse String	58.90%	Easy
343	Integer Break	43.60%	Medium
342	Power of Four	34.10%	Easy
341	Flatten Nested List Iterator $	18.70%	Medium
340	Longest Substring with At Most K Distinct Characters $	36.30%	Hard
339	Nested List Weight Sum $	54.60%	Easy
338	Counting Bits	55.40%	Medium
337	House Robber III	37.00%	Medium
336	Palindrome Pairs	18.70%	Hard
335	Self Crossing	18.00%	Medium
334	Increasing Triplet Subsequence	33.20%	Medium
333	Largest BST Subtree $	26.50%	Medium
332	Reconstruct Itinerary	23.40%	Medium
331	Verify Preorder Serialization of a Binary Tree	31.50%	Medium
330	Patching Array	28.80%	Medium
329	Longest Increasing Path in a Matrix	29.50%	Medium
328	Odd Even Linked List	37.80%	Easy
327	Count of Range Sum	24.30%	Hard
326	Power of Three	35.30%	Easy
325	Maximum Size Subarray Sum Equals k $	39.60%	Easy
324	Wiggle Sort II	20.10%	Medium
323	Number of Connected Components in an Undirected Graph $	43.30%	Medium
322	Coin Change	24.90%	Medium
321	Create Maximum Number	19.10%	Hard
320	Generalized Abbreviation $	40.40%	Medium
319	Bulb Switcher	39.20%	Medium
318	Maximum Product of Word Lengths	38.70%	Medium
317	Shortest Distance from All Buildings $	29.10%	Hard
316	Remove Duplicate Letters	23.00%	Medium
315	Count of Smaller Numbers After Self	28.20%	Hard
314	Binary Tree Vertical Order Traversal $	30.10%	Medium
313	Super Ugly Number	31.20%	Medium
312	Burst Balloons	24.50%	Medium
311	Sparse Matrix Multiplication $	40.00%	Medium
310	Minimum Height Trees	20.20%	Medium
309	Best Time to Buy and Sell Stock with Cooldown	32.60%	Medium
308	Range Sum Query 2D - Mutable $	20.30%	Hard
307	Range Sum Query - Mutable	14.50%	Medium
306	Additive Number	23.30%	Medium
305	Number of Islands II $	26.70%	Hard
304	Range Sum Query 2D - Immutable	21.50%	Medium
303	Range Sum Query - Immutable	25.70%	Easy
302	Smallest Rectangle Enclosing Black Pixels $	36.70%	Hard
301	Remove Invalid Parentheses	27.00%	Hard
300	Longest Increasing Subsequence	31.50%	Medium
299	Bulls and Cows	23.80%	Easy
298	Binary Tree Longest Consecutive Sequence $	32.20%	Medium
297	Serialize and Deserialize Binary Tree	23.80%	Medium
296	Best Meeting Point $	41.40%	Hard
295	Find Median from Data Stream	18.60%	Hard
294	Flip Game II $	38.10%	Medium
293	Flip Game $	47.60%	Easy
292	Nim Game	49.50%	Easy
291	Word Pattern II $	31.50%	Hard
290	Word Pattern	26.50%	Easy
289	Game of Life	32.60%	Medium
288	Unique Word Abbreviation $	16.80%	Easy
287	Find the Duplicate Number	32.80%	Hard
286	Walls and Gates $	29.90%	Medium
285	Inorder Successor in BST $	32.50%	Medium
284	Peeking Iterator	31.00%	Medium
283	Move Zeroes	41.40%	Easy
282	Expression Add Operators	18.90%	Hard
281	Zigzag Iterator $	37.20%	Medium
280	Wiggle Sort $	43.30%	Medium
279	Perfect Squares	28.80%	Medium
278	First Bad Version	19.80%	Easy
277	Find the Celebrity $	31.70%	Medium
276	Paint Fence $	25.00%	Easy
275	H-Index II	31.40%	Medium
274	H-Index	25.30%	Medium
273	Integer to English Words	15.50%	Medium
272	Closest Binary Search Tree Value II $	26.90%	Hard
271	Encode and Decode Strings $	25.40%	Medium
270	Closest Binary Search Tree Value $	29.40%	Easy
269	Alien Dictionary $	16.50%	Hard
268	Missing Number	34.70%	Medium
267	Palindrome Permutation II $	22.50%	Medium
266	Palindrome Permutation $	45.80%	Easy
265	Paint House II $	30.00%	Hard
264	Ugly Number II	21.60%	Medium
263	Ugly Number	32.60%	Easy
262	Trips and Users *	16.10%	Hard
261	Graph Valid Tree $	25.40%	Medium
260	Single Number III	37.60%	Medium
259	3Sum Smaller $	34.20%	Medium
258	Add Digits	46.50%	Easy
257	Binary Tree Paths	21.90%	Easy
256	Paint House $	38.40%	Medium
255	Verify Preorder Sequence in Binary Search Tree $	32.30%	Medium
254	Factor Combinations $	29.00%	Medium
253	Meeting Rooms II $	28.80%	Medium
252	Meeting Rooms $	35.40%	Easy
251	Flatten 2D Vector $	28.30%	Medium
250	Count Univalue Subtrees $	32.70%	Medium
249	Group Shifted Strings $	25.20%	Easy
248	Strobogrammatic Number III $	21.80%	Hard
247	Strobogrammatic Number II $	26.70%	Medium
246	Strobogrammatic Number $	31.60%	Easy
245	Shortest Word Distance III $	43.20%	Medium
244	Shortest Word Distance II $	33.70%	Medium
243	Shortest Word Distance $	41.80%	Easy
242	Valid Anagram	39.30%	Easy
241	Different Ways to Add Parentheses	27.10%	Medium
240	Search a 2D Matrix II	31.40%	Medium
239	Sliding Window Maximum	24.30%	Hard
238	Product of Array Except Self	42.40%	Medium
237	Delete Node in a Linked List	50.90%	Easy
236	Lowest Common Ancestor of a Binary Tree	28.30%	Medium
235	Lowest Common Ancestor of a Binary Search Tree	38.90%	Medium
234	Palindrome Linked List	23.80%	Easy
233	Number of Digit One	16.10%	Medium
232	Implement Queue using Stacks	37.40%	Easy
231	Power of Two	31.30%	Easy
230	Kth Smallest Element in a BST	30.50%	Medium
229	Majority Element II	30.50%	Medium
228	Summary Ranges	21.10%	Easy
227	Basic Calculator II	18.00%	Medium
226	Invert Binary Tree	35.40%	Easy
225	Implement Stack using Queues	29.60%	Medium
224	Basic Calculator	15.80%	Medium
223	Rectangle Area	25.60%	Easy
222	Count Complete Tree Nodes	19.40%	Medium
221	Maximal Square	20.30%	Medium
220	Contains Duplicate III	15.30%	Medium
219	Contains Duplicate II	25.60%	Easy
218	The Skyline Problem	16.20%	Hard
217	Contains Duplicate	35.90%	Easy
216	Combination Sum III	27.70%	Medium
215	Kth Largest Element in an Array	27.30%	Medium
214	Shortest Palindrome	16.80%	Hard
213	House Robber II	26.30%	Medium
212	Word Search II	15.00%	Hard
211	Add and Search Word - Data structure design	20.70%	Medium
210	Course Schedule II	19.30%	Medium
209	Minimum Size Subarray Sum	22.90%	Medium
208	Implement Trie (Prefix Tree)	24.80%	Medium
207	Course Schedule	21.70%	Medium
206	Reverse Linked List	31.50%	Easy
205	Isomorphic Strings	24.20%	Easy
204	Count Primes	19.00%	Easy
203	Remove Linked List Elements	25.80%	Easy
202	Happy Number	31.40%	Easy
201	Bitwise AND of Numbers Range	23.30%	Medium
200	Number of Islands	21.90%	Medium
199	Binary Tree Right Side View	27.10%	Medium
198	House Robber	28.80%	Easy
197	Rising Temperature *	25.90%	Easy
196	Delete Duplicate Emails *	19.00%	Easy
195	Tenth Line #	32.20%	Easy
194	Transpose File #	21.40%	Medium
193	Valid Phone Numbers #	24.40%	Easy
192	Word Frequency #	26.10%	Medium
191	Number of 1 Bits	37.30%	Easy
190	Reverse Bits	28.40%	Easy
189	Rotate Array	17.80%	Easy
188	Best Time to Buy and Sell Stock IV	17.30%	Hard
187	Repeated DNA Sequences	19.50%	Medium
186	Reverse Words in a String II $	31.10%	Medium
185	Department Top Three Salaries *	15.20%	Hard
184	Department Highest Salary *	19.00%	Medium
183	Customers Who Never Order *	33.70%	Easy
182	Duplicate Emails *	38.10%	Easy
181	Employees Earning More Than Their Managers *	41.00%	Easy
180	Consecutive Numbers *	26.60%	Medium
179	Largest Number	15.70%	Medium
178	Rank Scores *	24.60%	Medium
177	Nth Highest Salary *	16.30%	Medium
176	Second Highest Salary *	25.00%	Easy
175	Combine Two Tables *	34.40%	Easy
174	Dungeon Game	17.70%	Hard
173	Binary Search Tree Iterator	29.30%	Medium
172	Factorial Trailing Zeroes	28.40%	Easy
171	Excel Sheet Column Number	36.50%	Easy
170	Two Sum III - Data structure design $	24.70%	Easy
169	Majority Element	35.00%	Easy
168	Excel Sheet Column Title	18.10%	Easy
167	Two Sum II - Input array is sorted $	43.30%	Medium
166	Fraction to Recurring Decimal	12.70%	Medium
165	Compare Version Numbers	15.20%	Easy
164	Maximum Gap	24.40%	Hard
163	Missing Ranges $	24.10%	Medium
162	Find Peak Element	31.50%	Medium
161	One Edit Distance $	24.00%	Medium
160	Intersection of Two Linked Lists	28.70%	Easy
159	Longest Substring with At Most Two Distinct Characters $	30.20%	Hard
158	Read N Characters Given Read4 II - Call multiple times $	22.30%	Hard
157	Read N Characters Given Read4 $	29.80%	Easy
156	Binary Tree Upside Down $	34.30%	Medium
155	Min Stack	18.50%	Easy
154	Find Minimum in Rotated Sorted Array II	31.90%	Hard
153	Find Minimum in Rotated Sorted Array	33.30%	Medium
152	Maximum Product Subarray	19.40%	Medium
151	Reverse Words in a String	15.10%	Medium
150	Evaluate Reverse Polish Notation	21.10%	Medium
149	Max Points on a Line	12.60%	Hard
148	Sort List	22.00%	Medium
147	Insertion Sort List	26.40%	Medium
146	LRU Cache	15.00%	Hard
145	Binary Tree Postorder Traversal	32.40%	Hard
144	Binary Tree Preorder Traversal	36.30%	Medium
143	Reorder List	21.00%	Medium
142	Linked List Cycle II	31.40%	Medium
141	Linked List Cycle	36.30%	Medium
140	Word Break II	17.70%	Hard
139	Word Break	23.00%	Medium
138	Copy List with Random Pointer	25.10%	Hard
137	Single Number II	35.00%	Medium
136	Single Number	45.10%	Medium
135	Candy	20.50%	Hard
134	Gas Station	25.70%	Medium
133	Clone Graph	24.00%	Medium
132	Palindrome Partitioning II	19.70%	Hard
131	Palindrome Partitioning	26.70%	Medium
130	Surrounded Regions	14.60%	Medium
129	Sum Root to Leaf Numbers	30.30%	Medium
128	Longest Consecutive Sequence	29.40%	Hard
127	Word Ladder	19.30%	Medium
126	Word Ladder II	12.90%	Hard
125	Valid Palindrome	22.00%	Easy
124	Binary Tree Maximum Path Sum	21.50%	Hard
123	Best Time to Buy and Sell Stock III	23.90%	Hard
122	Best Time to Buy and Sell Stock II	38.30%	Medium
121	Best Time to Buy and Sell Stock	32.60%	Medium
120	Triangle	27.40%	Medium
119	Pascal's Triangle II	29.40%	Easy
118	Pascal's Triangle	30.10%	Easy
117	Populating Next Right Pointers in Each Node II	32.00%	Hard
116	Populating Next Right Pointers in Each Node	36.20%	Medium
115	Distinct Subsequences	26.30%	Hard
114	Flatten Binary Tree to Linked List	28.80%	Medium
113	Path Sum II	26.60%	Medium
112	Path Sum	29.80%	Easy
111	Minimum Depth of Binary Tree	29.10%	Easy
110	Balanced Binary Tree	32.00%	Easy
109	Convert Sorted List to Binary Search Tree	27.90%	Medium
108	Convert Sorted Array to Binary Search Tree	34.00%	Medium
107	Binary Tree Level Order Traversal II	31.10%	Easy
106	Construct Binary Tree from Inorder and Postorder Traversal	26.80%	Medium
105	Construct Binary Tree from Preorder and Inorder Traversal	26.40%	Medium
104	Maximum Depth of Binary Tree	45.10%	Easy
103	Binary Tree Zigzag Level Order Traversal	26.40%	Medium
102	Binary Tree Level Order Traversal	29.30%	Easy
101	Symmetric Tree	31.60%	Easy
100	Same Tree	41.80%	Easy
99	Recover Binary Search Tree	24.30%	Hard
98	Validate Binary Search Tree	20.60%	Medium
97	Interleaving String	20.80%	Hard
96	Unique Binary Search Trees	36.00%	Medium
95	Unique Binary Search Trees II	28.00%	Medium
94	Binary Tree Inorder Traversal	36.20%	Medium
93	Restore IP Addresses	21.00%	Medium
92	Reverse Linked List II	26.10%	Medium
91	Decode Ways	16.40%	Medium
90	Subsets II	27.70%	Medium
89	Gray Code	32.80%	Medium
88	Merge Sorted Array	29.70%	Easy
87	Scramble String	24.20%	Hard
86	Partition List	27.50%	Medium
85	Maximal Rectangle	22.00%	Hard
84	Largest Rectangle in Histogram	22.60%	Hard
83	Remove Duplicates from Sorted List	34.50%	Easy
82	Remove Duplicates from Sorted List II	25.00%	Medium
81	Search in Rotated Sorted Array II	31.40%	Medium
80	Remove Duplicates from Sorted Array II	30.50%	Medium
79	Word Search	20.30%	Medium
78	Subsets	28.20%	Medium
77	Combinations	30.90%	Medium
76	Minimum Window Substring	18.90%	Hard
75	Sort Colors	32.60%	Medium
74	Search a 2D Matrix	31.60%	Medium
73	Set Matrix Zeroes	31.40%	Medium
72	Edit Distance	26.20%	Hard
71	Simplify Path	20.00%	Medium
70	Climbing Stairs	34.40%	Easy
69	Sqrt(x)	23.10%	Medium
68	Text Justification	14.60%	Hard
67	Add Binary	24.70%	Easy
66	Plus One	30.40%	Easy
65	Valid Number	11.40%	Hard
64	Minimum Path Sum	32.20%	Medium
63	Unique Paths II	28.00%	Medium
62	Unique Paths	32.80%	Medium
61	Rotate List	21.70%	Medium
60	Permutation Sequence	22.80%	Medium
59	Spiral Matrix II	31.80%	Medium
58	Length of Last Word	28.00%	Easy
57	Insert Interval	21.40%	Hard
56	Merge Intervals	22.40%	Hard
55	Jump Game	27.00%	Medium
54	Spiral Matrix	20.80%	Medium
53	Maximum Subarray	34.50%	Medium
52	N-Queens II	35.80%	Hard
51	N-Queens	26.50%	Hard
50	"Pow(x	n)"	26.70%
49	Anagrams	24.30%	Medium
48	Rotate Image	31.90%	Medium
47	Permutations II	25.80%	Hard
46	Permutations	31.90%	Medium
45	Jump Game II	24.20%	Hard
44	Wildcard Matching	15.00%	Hard
43	Multiply Strings	21.00%	Medium
42	Trapping Rain Water	30.00%	Hard
41	First Missing Positive	22.90%	Hard
40	Combination Sum II	25.20%	Medium
39	Combination Sum	27.90%	Medium
38	Count and Say	25.20%	Easy
37	Sudoku Solver	21.80%	Hard
36	Valid Sudoku	27.20%	Easy
35	Search Insert Position	35.40%	Medium
34	Search for a Range	27.50%	Medium
33	Search in Rotated Sorted Array	28.80%	Hard
32	Longest Valid Parentheses	20.90%	Hard
31	Next Permutation	25.00%	Medium
30	Substring with Concatenation of All Words	19.40%	Hard
29	Divide Two Integers	15.00%	Medium
28	Implement strStr()	22.20%	Easy
27	Remove Element	32.10%	Easy
26	Remove Duplicates from Sorted Array	31.30%	Easy
25	Reverse Nodes in k-Group	25.50%	Hard
24	Swap Nodes in Pairs	32.50%	Medium
23	Merge k Sorted Lists	21.10%	Hard
22	Generate Parentheses	32.60%	Medium
21	Merge Two Sorted Lists	32.70%	Easy
20	Valid Parentheses	26.50%	Easy
19	Remove Nth Node From End of List	27.10%	Easy
18	4Sum	21.70%	Medium
17	Letter Combinations of a Phone Number	25.80%	Medium
16	3Sum Closest	26.90%	Medium
15	3Sum	16.90%	Medium
14	Longest Common Prefix	25.50%	Easy
13	Roman to Integer	34.00%	Easy
12	Integer to Roman	33.80%	Medium
11	Container With Most Water	32.00%	Medium
10	Regular Expression Matching	20.70%	Hard
9	Palindrome Number	28.30%	Easy
8	String to Integer (atoi)	13.00%	Easy
7	Reverse Integer	25.10%	Easy
6	ZigZag Conversion	21.80%	Easy
5	Longest Palindromic Substring	20.70%	Medium
4	Median of Two Sorted Arrays	17.40%	Hard
3	Longest Substring Without Repeating Characters	20.60%	Medium
2	Add Two Numbers	21.10%	Medium
1	Two Sum	17.70%	Medium

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