| 1 |
Two Sum |
Easy |
001_two-sum |
| 2 |
Add Two Numbers |
Medium |
002_add-two-numbers |
| 3 |
Longest Substring Without Repeating Characters |
Medium |
003_longest-substring-without-repeating-characters |
| 5 |
Longest Palindromic Substring |
Medium |
005_longest-palindromic-substring |
| 6 |
ZigZag Conversion |
Medium |
006_zigzag-conversion |
| 7 |
Reverse Integer |
Easy |
007_reverse-integer |
| 8 |
String to Integer (atoi) |
Medium |
008_string-to-integer-atoi |
| 9 |
Palindrome Number |
Easy |
009_palindrome-number |
| 10 |
Regular Expression Matching |
Hard |
010_regular-expression-matching |
| 11 |
Container With Most Water |
Medium |
011_container-with-most-water |
| 12 |
Integer to Roman |
Medium |
012_integer-to-roman |
| 13 |
Roman to Integer |
Easy |
013_roman-to-integer |
| 14 |
Longest Common Prefix |
Easy |
014_longest-common-prefix |
| 15 |
3Sum |
Medium |
015_3sum |
| 16 |
3Sum Closest |
Medium |
016_3sum-closest |
| 17 |
Letter Combinations of a Phone Number |
Medium |
017_letter-combinations-of-a-phone-number |
| 18 |
4Sum |
Medium |
018_4sum |
| 19 |
Remove Nth Node From End of List |
Medium |
019_remove-nth-node-from-end-of-list |
| 20 |
Valid Parentheses |
Easy |
020_valid-parentheses |
| 21 |
Merge Two Sorted Lists |
Easy |
021_merge-two-sorted-lists |
| 22 |
Generate Parentheses |
Medium |
022_generate-parentheses |
| 23 |
Merge k Sorted Lists |
Hard |
023_merge-k-sorted-lists |
| 24 |
Swap Nodes in Pairs |
Medium |
024_swap-nodes-in-pairs |
| 26 |
Remove Duplicates from Sorted Array |
Easy |
026_remove-duplicates-from-sorted-array |
| 27 |
Remove Element |
Easy |
027_remove-element |
| 28 |
Implement strStr() |
Easy |
028_implement-strstr |
| 29 |
Divide Two Integers |
Medium |
029_divide-two-integers |
| 34 |
Search for a Range |
Medium |
034_search-for-a-range |
| 35 |
Search Insert Position |
Easy |
035_search-insert-position |
| 38 |
Count and Say |
Easy |
038_count-and-say |
| 39 |
Combination Sum |
Medium |
039_combination-sum |
| 41 |
First Missing Positive |
Hard |
041_first-missing-positive |
| 46 |
Permutations |
Medium |
046_permutations |
| 48 |
Rotate Image |
Medium |
048_rotate-image |
| 49 |
Group Anagrams |
Medium |
049_group-anagrams |
| 53 |
Maximum Subarray |
Easy |
053_maximum-subarray |
| 54 |
Spiral Matrix |
Medium |
054_spiral-matrix |
| 55 |
Jump Game |
Medium |
055_jump-game |
| 58 |
Length of Last Word |
Easy |
058_length-of-last-word |
| 59 |
Spiral Matrix II |
Medium |
059_spiral-matrix-ii |
| 60 |
Permutation Sequence |
Medium |
060_permutation-sequence |
| 61 |
Rotate List |
Medium |
061_rotate-list |
| 62 |
Unique Paths |
Medium |
062_unique-paths |
| 63 |
Unique Paths II |
Medium |
063_unique-paths-ii |
| 64 |
Minimum Path Sum |
Medium |
064_minimum-path-sum |
| 68 |
Text Justification |
Hard |
068_text-justification |
| 69 |
Sqrt(x) |
Easy |
069_sqrtx |
| 71 |
Simplify Path |
Medium |
071_simplify-path |
| 73 |
Set Matrix Zeroes |
Medium |
073_set-matrix-zeroes |
| 75 |
Sort Colors |
Medium |
075_sort-colors |
| 77 |
Combinations |
Medium |
077_combinations |
| 78 |
Subsets |
Medium |
078_subsets |
| 79 |
Word Search |
Medium |
079_word-search |
| 80 |
Remove Duplicates from Sorted Array II |
Medium |
080_remove-duplicates-from-sorted-array-ii |
| 83 |
Remove Duplicates from Sorted List |
Easy |
083_remove-duplicates-from-sorted-list |
| 88 |
Merge Sorted Array |
Easy |
088_merge-sorted-array |
| 89 |
Gray Code |
Medium |
089_gray-code |
| 90 |
Subsets II |
Medium |
090_subsets-ii |
| 91 |
Decode Ways |
Medium |
091_decode-ways |
| 92 |
Reverse Linked List II |
Medium |
092_reverse-linked-list-ii |
| 93 |
Restore IP Addresses |
Medium |
093_restore-ip-addresses |
| 94 |
Binary Tree Inorder Traversal |
Medium |
094_binary-tree-inorder-traversal |
| 98 |
Validate Binary Search Tree |
Medium |
098_validate-binary-search-tree |
| 100 |
Same Tree |
Easy |
100_same-tree |
| 101 |
Symmetric Tree |
Easy |
101_symmetric-tree |
| 102 |
Binary Tree Level Order Traversal |
Medium |
102_binary-tree-level-order-traversal |
| 111 |
Minimum Depth of Binary Tree |
Easy |
111_minimum-depth-of-binary-tree |
| 112 |
Path Sum |
Easy |
112_path-sum |
| 113 |
Path Sum II |
Medium |
113_path-sum-ii |
| 114 |
Flatten Binary Tree to Linked List |
Medium |
114_flatten-binary-tree-to-linked-list |
| 116 |
Populating Next Right Pointers in Each Node |
Medium |
116_populating-next-right-pointers-in-each-node |
| 118 |
Pascal's Triangle |
Easy |
118_pascals-triangle |
| 119 |
Pascal's Triangle II |
Easy |
119_pascals-triangle-ii |
| 120 |
Triangle |
Medium |
120_triangle |
| 121 |
Best Time to Buy and Sell Stock |
Easy |
121_best-time-to-buy-and-sell-stock |
| 122 |
Best Time to Buy and Sell Stock II |
Easy |
122_best-time-to-buy-and-sell-stock-ii |
| 125 |
Valid Palindrome |
Easy |
125_valid-palindrome |
| 129 |
Sum Root to Leaf Numbers |
Medium |
129_sum-root-to-leaf-numbers |
| 130 |
Surrounded Regions |
Medium |
130_surrounded-regions |
| 131 |
Palindrome Partitioning |
Medium |
131_palindrome-partitioning |
| 134 |
Gas Station |
Medium |
134_gas-station |
| 136 |
Single Number |
Easy |
136_single-number |
| 137 |
Single Number II |
Medium |
137_single-number-ii |
| 139 |
Word Break |
Medium |
139_word-break |
| 141 |
Linked List Cycle |
Easy |
141_linked-list-cycle |
| 142 |
Linked List Cycle II |
Medium |
142_linked-list-cycle-ii |
| 143 |
Reorder List |
Medium |
143_reorder-list |
| 144 |
Binary Tree Preorder Traversal |
Medium |
144_binary-tree-preorder-traversal |
| 145 |
Binary Tree Postorder Traversal |
Hard |
145_binary-tree-postorder-traversal |
| 147 |
Insertion Sort List |
Medium |
147_insertion-sort-list |
| 150 |
Evaluate Reverse Polish Notation |
Medium |
150_evaluate-reverse-polish-notation |
| 151 |
Reverse Words in a String |
Medium |
151_reverse-words-in-a-string |
| 152 |
Maximum Product Subarray |
Medium |
152_maximum-product-subarray |
| 153 |
Find Minimum in Rotated Sorted Array |
Medium |
153_find-minimum-in-rotated-sorted-array |
| 155 |
Min Stack |
Easy |
155_min-stack |
| 160 |
Intersection of Two Linked Lists |
Easy |
160_intersection-of-two-linked-lists |
| 162 |
Find Peak Element |
Medium |
162_find-peak-element |
| 165 |
Compare Version Numbers |
Medium |
165_compare-version-numbers |
| 168 |
Excel Sheet Column Title |
Easy |
168_excel-sheet-column-title |
| 169 |
Majority Element |
Easy |
169_majority-element |
| 171 |
Excel Sheet Column Number |
Easy |
171_excel-sheet-column-number |
| 172 |
Factorial Trailing Zeroes |
Easy |
172_factorial-trailing-zeroes |
| 179 |
Largest Number |
Medium |
179_largest-number |
| 187 |
Repeated DNA Sequences |
Medium |
187_repeated-dna-sequences |
| 189 |
Rotate Array |
Easy |
189_rotate-array |
| 190 |
Reverse Bits |
Easy |
190_reverse-bits |
| 191 |
Number of 1 Bits |
Easy |
191_number-of-1-bits |
| 198 |
House Robber |
Easy |
198_house-robber |
| 199 |
Binary Tree Right Side View |
Medium |
199_binary-tree-right-side-view |
| 200 |
Number of Islands |
Medium |
200_number-of-islands |
| 201 |
Bitwise AND of Numbers Range |
Medium |
201_bitwise-and-of-numbers-range |
| 202 |
Happy Number |
Easy |
202_happy-number |
| 203 |
Remove Linked List Elements |
Easy |
203_remove-linked-list-elements |
| 204 |
Count Primes |
Easy |
204_count-primes |
| 205 |
Isomorphic Strings |
Easy |
205_isomorphic-strings |
| 206 |
Reverse Linked List |
Easy |
206_reverse-linked-list |
| 207 |
Course Schedule |
Medium |
207_course-schedule |
| 209 |
Minimum Size Subarray Sum |
Medium |
209_minimum-size-subarray-sum |
| 215 |
Kth Largest Element in an Array |
Medium |
215_kth-largest-element-in-an-array |
| 216 |
Combination Sum III |
Medium |
216_combination-sum-iii |
| 217 |
Contains Duplicate |
Easy |
217_contains-duplicate |
| 219 |
Contains Duplicate II |
Easy |
219_contains-duplicate-ii |
| 220 |
Contains Duplicate III |
Medium |
220_contains-duplicate-iii |
| 221 |
Maximal Square |
Medium |
221_maximal-square |
| 223 |
Rectangle Area |
Medium |
223_rectangle-area |
| 224 |
Basic Calculator |
Hard |
224_basic-calculator |
| 226 |
Invert Binary Tree |
Easy |
226_invert-binary-tree |
| 227 |
Basic Calculator II |
Medium |
227_basic-calculator-ii |
| 228 |
Summary Ranges |
Medium |
228_summary-ranges |
| 229 |
Majority Element II |
Medium |
229_majority-element-ii |
| 231 |
Power of Two |
Easy |
231_power-of-two |
| 234 |
Palindrome Linked List |
Easy |
234_palindrome-linked-list |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
Easy |
235_lowest-common-ancestor-of-a-binary-search-tree |
| 237 |
Delete Node in a Linked List |
Easy |
237_delete-node-in-a-linked-list |
| 238 |
Product of Array Except Self |
Medium |
238_product-of-array-except-self |
| 240 |
Search a 2D Matrix II |
Medium |
240_search-a-2d-matrix-ii |
| 242 |
Valid Anagram |
Easy |
242_valid-anagram |
| 257 |
Binary Tree Paths |
Easy |
257_binary-tree-paths |
| 258 |
Add Digits |
Easy |
258_add-digits |
| 263 |
Ugly Number |
Easy |
263_ugly-number |
| 264 |
Ugly Number II |
Medium |
264_ugly-number-ii |
| 268 |
Missing Number |
Easy |
268_missing-number |
| 274 |
H-Index |
Medium |
274_h-index |
| 275 |
H-Index II |
Medium |
275_h-index-ii |
| 278 |
First Bad Version |
Easy |
278_first-bad-version |
| 279 |
Perfect Squares |
Medium |
279_perfect-squares |
| 283 |
Move Zeroes |
Easy |
283_move-zeroes |
| 289 |
Game of Life |
Medium |
289_game-of-life |
| 290 |
Word Pattern |
Easy |
290_word-pattern |
| 292 |
Nim Game |
Easy |
292_nim-game |
| 299 |
Bulls and Cows |
Medium |
299_bulls-and-cows |
| 300 |
Longest Increasing Subsequence |
Medium |
300_longest-increasing-subsequence |
| 303 |
Range Sum Query - Immutable |
Easy |
303_range-sum-query-immutable |
| 304 |
Range Sum Query 2D - Immutable |
Medium |
304_range-sum-query-2d-immutable |
| 306 |
Additive Number |
Medium |
306_additive-number |
| 307 |
Range Sum Query - Mutable |
Medium |
307_range-sum-query-mutable |
| 318 |
Maximum Product of Word Lengths |
Medium |
318_maximum-product-of-word-lengths |
| 322 |
Coin Change |
Medium |
322_coin-change |
| 326 |
Power of Three |
Easy |
326_power-of-three |
| 328 |
Odd Even Linked List |
Medium |
328_odd-even-linked-list |
| 332 |
Reconstruct Itinerary |
Medium |
332_reconstruct-itinerary |
| 334 |
Increasing Triplet Subsequence |
Medium |
334_increasing-triplet-subsequence |
| 338 |
Counting Bits |
Medium |
338_counting-bits |
| 343 |
Integer Break |
Medium |
343_integer-break |
| 344 |
Reverse String |
Easy |
344_reverse-string |
| 345 |
Reverse Vowels of a String |
Easy |
345_reverse-vowels-of-a-string |
| 347 |
Top K Frequent Elements |
Medium |
347_top-k-frequent-elements |
| 349 |
Intersection of Two Arrays |
Easy |
349_intersection-of-two-arrays |
| 350 |
Intersection of Two Arrays II |
Easy |
350_intersection-of-two-arrays-ii |
| 367 |
Valid Perfect Square |
Easy |
367_valid-perfect-square |
| 368 |
Largest Divisible Subset |
Medium |
368_largest-divisible-subset |
| 378 |
Kth Smallest Element in a Sorted Matrix |
Medium |
378_kth-smallest-element-in-a-sorted-matrix |
| 383 |
Ransom Note |
Easy |
383_ransom-note |
| 386 |
Lexicographical Numbers |
Medium |
386_lexicographical-numbers |
| 387 |
First Unique Character in a String |
Easy |
387_first-unique-character-in-a-string |
| 388 |
Longest Absolute File Path |
Medium |
388_longest-absolute-file-path |
| 389 |
Find the Difference |
Easy |
389_find-the-difference |
| 392 |
Is Subsequence |
Medium |
392_is-subsequence |
| 394 |
Decode String |
Medium |
394_decode-string |
| 397 |
Integer Replacement |
Medium |
397_integer-replacement |
| 399 |
Evaluate Division |
Medium |
399_evaluate-division |
| 401 |
Binary Watch |
Easy |
401_binary-watch |
| 404 |
Sum of Left Leaves |
Easy |
404_sum-of-left-leaves |
| 405 |
Convert a Number to Hexadecimal |
Easy |
405_convert-a-number-to-hexadecimal |
| 406 |
Queue Reconstruction by Height |
Medium |
406_queue-reconstruction-by-height |
| 409 |
Longest Palindrome |
Easy |
409_longest-palindrome |
| 412 |
Fizz Buzz |
Easy |
412_fizz-buzz |
| 413 |
Arithmetic Slices |
Medium |
413_arithmetic-slices |
| 415 |
Add Strings |
Easy |
415_add-strings |
| 416 |
Partition Equal Subset Sum |
Medium |
416_partition-equal-subset-sum |
| 417 |
Pacific Atlantic Water Flow |
Medium |
417_pacific-atlantic-water-flow |
| 419 |
Battleships in a Board |
Medium |
419_battleships-in-a-board |
| 423 |
Reconstruct Original Digits from English |
Medium |
423_reconstruct-original-digits-from-english |
| 434 |
Number of Segments in a String |
Easy |
434_number-of-segments-in-a-string |
| 438 |
Find All Anagrams in a String |
Easy |
438_find-all-anagrams-in-a-string |
| 441 |
Arranging Coins |
Easy |
441_arranging-coins |
| 442 |
Find All Duplicates in an Array |
Medium |
442_find-all-duplicates-in-an-array |
| 453 |
Minimum Moves to Equal Array Elements |
Easy |
453_minimum-moves-to-equal-array-elements |
| 485 |
Max Consecutive Ones |
Easy |
485_max-consecutive-ones |
| 492 |
Construct the Rectangle |
Easy |
492_construct-the-rectangle |
| 494 |
Target Sum |
Medium |
494_target-sum |
| 496 |
Next Greater Element I |
Easy |
496_next-greater-element-i |
| 506 |
Relative Ranks |
Easy |
506_relative-ranks |
| 508 |
Most Frequent Subtree Sum |
Medium |
508_most-frequent-subtree-sum |
| 513 |
Find Bottom Left Tree Value |
Medium |
513_find-bottom-left-tree-value |
| 515 |
Find Largest Value in Each Tree Row |
Medium |
515_find-largest-value-in-each-tree-row |
| 520 |
Detect Capital |
Easy |
520_detect-capital |
| 529 |
Minesweeper |
Medium |
529_minesweeper |
| 530 |
Minimum Absolute Difference in BST |
Easy |
530_minimum-absolute-difference-in-bst |
| 538 |
Convert BST to Greater Tree |
Easy |
538_convert-bst-to-greater-tree |
| 539 |
Minimum Time Difference |
Medium |
539_minimum-time-difference |
| 542 |
01 Matrix |
Medium |
542_01-matrix |
| 560 |
Subarray Sum Equals K |
Medium |
560_subarray-sum-equals-k |
| 561 |
Array Partition I |
Easy |
561_array-partition-i |
| 563 |
Binary Tree Tilt |
Easy |
563_binary-tree-tilt |
| 566 |
Reshape the Matrix |
Easy |
566_reshape-the-matrix |
| 567 |
Permutation in String |
Medium |
567_permutation-in-string |
| 581 |
Shortest Unsorted Continuous Subarray |
Easy |
581_shortest-unsorted-continuous-subarray |
| 592 |
Fraction Addition and Subtraction |
Medium |
592_fraction-addition-and-subtraction |
| 593 |
Valid Square |
Medium |
593_valid-square |
| 594 |
Longest Harmonious Subsequence |
Easy |
594_longest-harmonious-subsequence |
| 617 |
Merge Two Binary Trees |
Easy |
617_merge-two-binary-trees |
| 646 |
Maximum Length of Pair Chain |
Medium |
646_maximum-length-of-pair-chain |
| 655 |
Print Binary Tree |
Medium |
655_print-binary-tree |
| 662 |
Maximum Width of Binary Tree |
Medium |
662_maximum-width-of-binary-tree |
| 669 |
Trim a Binary Search Tree |
Easy |
669_trim-a-binary-search-tree |
| 670 |
Maximum Swap |
Medium |
670_maximum-swap |
| 671 |
Second Minimum Node In a Binary Tree |
Easy |
671_second-minimum-node-in-a-binary-tree |
| 673 |
Number of Longest Increasing Subsequence |
Medium |
673_number-of-longest-increasing-subsequence |
| 674 |
Longest Continuous Increasing Subsequence |
Easy |
674_longest-continuous-increasing-subsequence |
| 676 |
Implement Magic Dictionary |
Medium |
676_implement-magic-dictionary |
| 677 |
Map Sum Pairs |
Medium |
677_map-sum-pairs |
| 678 |
Valid Parenthesis String |
Medium |
678_valid-parenthesis-string |
| 680 |
Valid Palindrome II |
Easy |
680_valid-palindrome-ii |
| 682 |
Baseball Game |
Easy |
682_baseball-game |
| 687 |
Longest Univalue Path |
Easy |
687_longest-univalue-path |
| 693 |
Binary Number with Alternating Bits |
Easy |
693_binary-number-with-alternating-bits |
| 695 |
Max Area of Island |
Easy |
695_max-area-of-island |
| 698 |
Partition to K Equal Sum Subsets |
Medium |
698_partition-to-k-equal-sum-subsets |
| 713 |
Subarray Product Less Than K |
Medium |
713_subarray-product-less-than-k |
| 714 |
Best Time to Buy and Sell Stock with Transaction Fee |
Medium |
714_best-time-to-buy-and-sell-stock-with-transaction-fee |
