001 |
Two Sum |
HT |
Click Here |
002 |
Add Two Numbers |
List,Math |
Click Here |
003 |
Longest Substring Without Repeati… |
HT,TP |
Click Here |
004 |
Median of Two Sorted Arrays |
|
Click Here |
005 |
Longest Palindromic Substring |
String ,DP |
Click Here |
006 |
ZigZag Conversion |
|
Click Here |
007 |
Reverse Integer |
Math |
Click Here |
008 |
String to Integer |
Math,String |
Click Here |
009 |
Palindrome Number |
Math |
Click Here |
010 |
Regular Expression Matching |
|
Click Here |
011 |
Container With Most Water |
|
Click Here |
012 |
Integer to Roman |
Math |
Click Here |
013 |
Roman to Integer |
Math |
Click Here |
014 |
Longest Common Prefix |
String |
Click Here |
015 |
3Sum |
TP |
Click Here |
016 |
3Sum Closest |
TP,Array |
Click Here |
017 |
Letter Combinations of a Phone Number |
Btr |
Click Here |
018 |
4Sum |
TP,Array |
Click Here |
019 |
Remove Nth Node From End of List |
List |
Click Here |
020 |
Valid Parentheses |
Stack,String |
Click Here |
021 |
Merge Two Sorted Lists |
List |
Click Here |
022 |
Generate Parentheses |
Backtracking |
Click Here |
023 |
Merge k Sorted Lists |
|
Click Here |
024 |
Swap Nodes in Pairs |
List |
Click Here |
025 |
Reverse Nodes in k-Group |
|
Click Here |
026 |
Remove Duplicates from Sorted Array |
TP,Array |
Click Here |
027 |
Remove Element |
TP |
Click Here |
028 |
Implement strStr() |
KMP,String |
Click Here |
029 |
Divide Two Integers |
|
Click Here |
030 |
Substring with Concatenation of A… |
|
Click Here |
031 |
Next Permutation |
Math |
Click Here |
032 |
Longest Valid Parentheses |
|
Click Here |
033 |
Search in Rotated Sorted Array |
|
Click Here |
034 |
Search for a Range |
BS |
Click Here |
035 |
Search Insert Position |
BS |
Click Here |
036 |
Valid Sudoku |
|
Click Here |
037 |
Sudoku Solver |
|
Click Here |
038 |
Count and Say |
String |
Click Here |
039 |
Combination Sum |
Btr |
Click Here |
040 |
Combination Sum II |
Btr |
Click Here |
041 |
First Missing Positive |
|
Click Here |
042 |
Trapping Rain Water |
|
Click Here |
043 |
Multiply Strings |
Math |
Click Here |
044 |
Wildcard Matching |
|
Click Here |
045 |
Jump Game II |
|
Click Here |
046 |
Permutations |
Backtracking |
Click Here |
047 |
Permutations II |
Btr |
Click Here |
048 |
Rotate Image |
Array |
Click Here |
049 |
Anagrams |
HT,String |
Click Here |
050 |
Pow(x, n) |
Math,BS |
Click Here |
051 |
N-Queens |
|
Click Here |
052 |
N-Queens II |
Btr |
Click Here |
053 |
Maximum Subarray |
DP |
Click Here |
054 |
Spiral Matrix |
Array |
Click Here |
055 |
Jump Game |
Greedy |
Click Here |
056 |
Merge Intervals |
|
Click Here |
057 |
Insert Interval |
|
Click Here |
058 |
Length of Last Word |
String |
Click Here |
059 |
Spiral Matrix II |
Array |
Click Here |
060 |
Permutation Sequence |
DFS,Math |
Click Here |
061 |
Rotate List |
List |
Click Here |
062 |
Unique Paths |
DP |
Click Here |
063 |
Unique Paths II |
DP |
Click Here |
064 |
Minimum Path Sum |
DP |
Click Here |
065 |
Valid Number |
|
Click Here |
066 |
Plus One |
Math |
Click Here |
067 |
Add Binary |
Math,String |
Click Here |
068 |
Text Justification |
|
Click Here |
069 |
Sqrt(x) |
Math |
Click Here |
070 |
Climbing Stairs |
DP |
Click Here |
071 |
Simplify Path |
|
Click Here |
072 |
Edit Distance |
|
Click Here |
073 |
Set Matrix Zeroes |
Array |
Click Here |
074 |
Search a 2D Matrix |
BS |
Click Here |
075 |
Sort Colors |
TP,Sort |
Click Here |
076 |
Minimum Window Substring |
|
Click Here |
077 |
Combinations |
Btr |
Click Here |
078 |
Subsets |
Btr |
Click Here |
079 |
Word Search |
|
Click Here |
080 |
Remove Duplicates from Sorted Array II |
TP,Array |
Click Here |
081 |
Search in Rotated Sorted Array II |
|
Click Here |
082 |
Remove Duplicates from Sorted List II |
|
Click Here |
083 |
Remove Duplicates from Sorted List |
List |
Click Here |
084 |
Largest Rectangle in Histogram |
|
Click Here |
085 |
Maximal Rectangle |
|
Click Here |
086 |
Partition List |
List,TP |
Click Here |
087 |
Scramble String |
|
Click Here |
088 |
Merge Sorted Array |
TP |
Click Here |
089 |
Gray Code |
Btr,Math |
Click Here |
090 |
Subsets II |
Btr |
Click Here |
091 |
Decode Ways |
|
Click Here |
092 |
Reverse Linked List II |
|
Click Here |
093 |
Restore IP Addresses |
|
Click Here |
094 |
Binary Tree Inorder Traversal |
Binary Tree |
Click Here |
096 |
Unique Binary Search Trees |
DP |
Click Here |
095 |
Unique Binary Search Trees II |
|
Click Here |
097 |
Interleaving String |
|
Click Here |
098 |
Validate Binary Search Tree |
|
Click Here |
099 |
Recover Binary Search Tree |
|
Click Here |
100 |
Same Tree |
DFS,Tree |
Click Here |
101 |
Symmetric Tree |
DFS,Tree |
Click Here |
102 |
Binary Tree Level Order Traversal |
BFS,Tree |
Click Here |
103 |
Binary Tree Zigzag Level Order Traversal |
BFS,Tree |
Click Here |
104 |
Maximum Depth of Binary Tree |
DFS,Tree |
Click Here |
105 |
Construct Binary Tree from Preord… |
Tree |
Click Here |
106 |
Construct Binary Tree from Inorde… |
Tree |
Click Here |
107 |
Binary Tree Level Order Traversal II |
BFS,Tree |
Click Here |
108 |
Convert Sorted Array to Binary Se… |
Tree ,BFS |
Click Here |
109 |
Convert Sorted List to Binary Sea… |
Tree,List |
Click Here |
110 |
Balanced Binary Tree |
DFS |
Click Here |
111 |
Minimum Depth of Binary Tree |
DFS,Tree |
Click Here |
112 |
Path Sum |
DFS,Tree |
Click Here |
113 |
Path Sum II |
DFS,Tree |
Click Here |
114 |
Flatten Binary Tree to Linked List |
DFS,Tree |
Click Here |
115 |
Distinct Subsequences |
|
Click Here |
116 |
Populating Next Right Pointers in… |
Tree ,BFS,DFS |
Click Here |
117 |
Populating Next Right Pointers in… |
Tree,BFS,DFS |
Click Here |
118 |
Pascals Triangle |
Array,Math |
Click Here |
119 |
Pascal’s Triangle II |
Array,Math |
Click Here |
120 |
Triangle |
DP |
Click Here |
121 |
Best Time to Buy and Sell Stock |
DP |
Click Here |
122 |
Best Time to Buy and Sell Stock II |
DP |
Click Here |
123 |
Best Time to Buy and Sell Stock III |
DP |
Click Here |
124 |
Binary Tree Maximum Path Sum |
|
Click Here |
125 |
Valid Palindrome |
TP,String |
Click Here |
126 |
Word Ladder |
|
Click Here |
127 |
Word Ladder II |
|
Click Here |
128 |
Longest Consecutive Sequence |
|
Click Here |
129 |
Sum Root to Leaf Numbers |
Tree,DFS |
Click Here |
130 |
Surrounded Regions |
BFS,Union |
Click Here |
131 |
Palindrome Partitioning |
|
Click Here |
132 |
Palindrome Partitioning II |
|
Click Here |
133 |
Clone Graph |
Graph,DFS,BFS |
Click Here |
134 |
Gas Station |
|
Click Here |
135 |
Candy |
|
Click Here |
136 |
Single Number |
HS,Bit |
Click Here |
137 |
Single Number II |
HS,Bit |
Click Here |
138 |
Copy List with Random Pointer |
|
Click Here |
139 |
Word Break |
|
Click Here |
140 |
Word Break II |
|
Click Here |
141 |
Linked List Cycle |
Linked List |
Click Here |
142 |
Linked List Cycle II |
Linked List |
Click Here |
143 |
Reorder List |
|
Click Here |
144 |
Binary Tree Preorder Traversal |
Binary Tree |
Click Here |
145 |
Binary Tree Postorder Traversal |
Binary Tree |
Click Here |
146 |
LRU Cache |
|
Click Here |
147 |
Insertion Sort List |
|
Click Here |
148 |
Sort List |
List |
Click Here |
149 |
Max Points on a Line |
|
Click Here |
150 |
Evaluate Reverse Polish Notation |
|
Click Here |
151 |
Reverse Words in a String |
String |
Click Here |
152 |
Maximum Product Subarray |
DP |
Click Here |
153 |
Find Minimum in Rotated Sorted Array |
|
Click Here |
154 |
Find Minimum in Rotated Sorted Array II |
|
Click Here |
155 |
Min Stack |
|
Click Here |
156 |
Binary Tree Upside Down $ |
|
Not Buy |
157 |
Read N Characters Given Read4 $ |
|
Not Buy |
158 |
Read N Characters Given Read4 II … $ |
|
Not Buy |
159 |
Longest Substring with At Most Tw… $ |
|
Not Buy |
160 |
Intersection of Two Linked Lists |
List |
Click Here |
161 |
One Edit Distance $ |
Not Buy |
Not Buy |
162 |
Find Peak Element |
BS |
Click Here |
163 |
Missing Ranges $ |
|
Not Buy |
164 |
Maximum Gap |
|
Click Here |
165 |
Compare Version Numbers |
|
Click Here |
166 |
Fraction to Recurring Decimal |
|
Click Here |
167 |
Two Sum II - Input array is sorted $ |
Not Buy |
Not Buy |
168 |
Excel Sheet Column Title |
Math |
Click Here |
169 |
Majority Element |
Math,Bit |
Click Here |
170 |
Two Sum III - Data structure design $ |
|
Not Buy |
171 |
Excel Sheet Column Number |
Math |
Click Here |
172 |
Factorial Trailing Zeroes |
|
Click Here |
173 |
Binary Search Tree Iterator |
Tree |
Click Here |
174 |
Dungeon Game |
|
Click Here |
175 |
Combine Two Tables |
|
Click Here |
176 |
Second Highest Salary |
|
Click Here |
177 |
Nth Highest Salary |
|
Click Here |
178 |
Rank Scores |
|
Click Here |
179 |
Largest Number |
Sort,String |
Click Here |
180 |
Consecutive Numbers |
|
Click Here |
181 |
Employees Earning More Than Their… |
|
Click Here |
182 |
Duplicate Emails |
|
Click Here |
183 |
Customers Who Never Order |
|
Click Here |
184 |
Department Highest Salary |
|
Click Here |
185 |
Department Top Three Salaries |
|
Click Here |
186 |
Reverse Words in a String II $ |
|
Not Buy |
187 |
Repeated DNA Sequences |
|
Click Here |
188 |
Best Time to Buy and Sell Stock IV |
DP |
Click Here |
189 |
Rotate Array |
Array |
Click Here |
190 |
Reverse Bits |
Bit |
Click Here |
191 |
Number of 1 Bits |
Bit |
Click Here |
192 |
Word Frequency |
|
Click Here |
193 |
Valid Phone Numbers |
|
Click Here |
194 |
Transpose File |
|
Click Here |
195 |
Tenth Line |
|
Click Here |
196 |
Delete Duplicate Emails |
|
Click Here |
197 |
Rising Temperature |
|
Click Here |
198 |
House Robber |
DP |
Click Here |
199 |
Binary Tree Right Side View |
Tree,BFS |
Click Here |
200 |
Number of Islands |
DFS,Union |
Click Here |
201 |
Bitwise AND of Numbers Range |
Bit |
Click Here |
202 |
Happy Number |
Hash |
Click Here |
203 |
Remove Linked List Elements |
List |
Click Here |
204 |
Count Primes |
Math |
Click Here |
205 |
Isomorphic Strings |
Hash Table |
Click Here |
206 |
Reverse Linked List |
List |
Click Here |
207 |
Course Schedule |
|
Click Here |
208 |
Implement Trie (Prefix Tree) |
|
Click Here |
209 |
Minimum Size Subarray Sum |
TP,BS |
Click Here |
210 |
Course Schedule II |
|
Click Here |
211 |
Add and Search Word - Data struct… |
|
Click Here |
212 |
Word Search II |
|
Click Here |
213 |
House Robber II |
DP |
Click Here |
214 |
Shortest Palindrome |
|
Click Here |
215 |
Kth Largest Element in an Array |
Heap, Quick Sort |
Click Here |
216 |
Combination Sum III |
Btr |
Click Here |
217 |
Contains Duplicate |
Hash |
Click Here |
218 |
The Skyline Problem |
|
Click Here |
219 |
Contains Duplicate II |
Hash |
Click Here |
220 |
Contains Duplicate III |
|
Click Here |
221 |
Maximal Square |
|
Click Here |
222 |
Count Complete Tree Nodes |
|
Click Here |
223 |
Rectangle Area |
Math |
Click Here |
224 |
Basic Calculator |
|
Click Here |
225 |
Implement Stack using Queues |
Stack,Queue |
Click Here |
226 |
Invert Binary Tree |
Tree |
Click Here |
227 |
Basic Calculator II |
|
Click Here |
228 |
Summary Ranges |
Two Points |
Click Here |
229 |
Majority Element II |
|
Click Here |
230 |
Kth Smallest Element in a BST |
Tree |
Click Here |
231 |
Power of Two |
Bit,Math |
Click Here |
232 |
Implement Queue using Stacks |
Queue,Stack |
Click Here |
233 |
Number of Digit One |
|
Click Here |
234 |
Palindrome Linked List |
List |
Click Here |
235 |
Lowest Common Ancestor of a Binar… |
Tree |
Click Here |
236 |
Lowest Common Ancestor of a Binary Tree |
Tree |
Click Here |
237 |
Delete Node in a Linked List |
List |
Click Here |
238 |
Product of Array Except Self |
Math |
Click Here |
239 |
Sliding Window Maximum |
|
Click Here |
240 |
Search a 2D Matrix II |
BS |
Click Here |
241 |
Different Ways to Add Parentheses |
Divide |
Click Here |
242 |
Valid Anagram |
Hash,Sort |
Click Here |
243 |
Shortest Word Distance |
|
Not Buy |
244 |
Shortest Word Distance II |
|
Not Buy |
245 |
Shortest Word Distance III |
|
Not Buy |
246 |
Strobogrammatic Number |
|
Not Buy |
247 |
Strobogrammatic Number II |
|
Not Buy |
248 |
Strobogrammatic Number III |
|
Not Buy |
249 |
Group Shifted Strings |
|
Not Buy |
250 |
Count Univalue Subtrees |
|
Not Buy |
251 |
Flatten 2D Vector |
|
Not Buy |
252 |
Meeting Rooms |
|
Not Buy |
253 |
Meeting Rooms II |
|
Not Buy |
254 |
Factor Combinations |
|
Not Buy |
255 |
Verify Preorder Sequence in Binary Search Tree |
|
Not Buy |
256 |
Paint House |
|
Click Here |
257 |
Binary Tree Paths |
DFS,Tree |
Click Here |
258 |
Add Digits |
Math |
Click Here |
259 |
3Sum Smaller |
|
Click Here |
260 |
Single Number III |
Hash,Bit |
Click Here |
261 |
Graph Valid Tree |
|
Click Here |
262 |
NULL |
NULL |
NULL |
263 |
Ugly Number |
Math |
Click Here |
264 |
Ugly Number II |
DP,Heap,Math |
Click Here |
266 |
Palindrome Permutation |
|
Click Here |
267 |
Palindrome Permutation II |
|
Click Here |
268 |
Missing Number |
Math,Bit |
Click Here |
269 |
Alien Dictionary |
|
Click Here |
270 |
Closest Binary Search Tree Value |
|
Click Here |
271 |
Encode and Decode Strings |
|
Click Here |
272 |
Closest Binary Search Tree Value II |
|
Click Here |
273 |
Integer to English Words |
|
Click Here |
274 |
H-Index |
Array |
Click Here |
275 |
H-Index II |
BS |
Click Here |
276 |
Paint Fence |
|
Click Here |
277 |
Find the Celebrity |
|
Click Here |
278 |
First Bad Version |
BS |
Click Here |
279 |
Perfect Squares |
|
Click Here |
280 |
Wiggle Sort |
|
Click Here |
281 |
Zigzag Iterator |
|
Click Here |
282 |
Expression Add Operators |
|
Click Here |
283 |
Move Zeroes |
TP |
Click Here |
284 |
Peeking Iterator |
|
Click Here |
285 |
Inorder Successor in BST |
|
Click Here |
286 |
Walls and Gates |
|
Click Here |
287 |
Find the Duplicate Number |
TP,BS |
Click Here |
288 |
Unique Word Abbreviation |
|
Click Here |
289 |
Game of Life |
|
Click Here |
290 |
Word Pattern |
Hash |
Click Here |
291 |
Word Pattern II |
|
Not Buy |
292 |
Nim Game |
|
Click Here |
293 |
Flip Game |
|
Click Here |
294 |
Flip Game II |
|
Click Here |
295 |
Find Median from Data Stream |
|
Click Here |
296 |
Best Meeting Point |
|
Click Here |
297 |
Serialize and Deserialize Binary Tree |
|
Click Here |
298 |
Binary Tree Longest Consecutive Sequence |
|
Click Here |
299 |
Bulls and Cows |
|
Click Here |
300 |
Longest Increasing Subsequence |
|
Click Here |
301 |
Remove Invalid Parentheses |
|
Click Here |
302 |
Smallest Rectangle Enclosing Black Pixels |
|
Click Here |
303 |
Range Sum Query - Immutable |
DP |
Click Here |
304 |
Range Sum Query 2D - Immutable |
|
Click Here |
305 |
Number of Islands II |
|
Click Here |
306 |
Additive Number |
|
Click Here |
307 |
Range Sum Query - Mutable |
|
Click Here |
308 |
Range Sum Query 2D - Mutable |
|
Click Here |
309 |
Best Time to Buy and Sell Stock.... |
|
Click Here |
310 |
Minimum Height Trees |
|
Click Here |
311 |
Sparse Matrix Multiplication |
|
Click Here |
312 |
Burst Balloons |
Math |
Click Here |
313 |
Super Ugly Number |
DP,Heap |
Click Here |
314 |
Binary Tree Vertical Order Traversal |
|
Click Here |
315 |
Count of Smaller Numbers After Self |
|
Click Here |
316 |
Remove Duplicate Letters |
|
Click Here |
317 |
Shortest Distance from All Buildings |
|
Click Here |
318 |
Maximum Product of Word Lengths |
String,Bit |
Click Here |
319 |
Bulb Switcher |
Math |
Click Here |
320 |
Generalized Abbreviation |
|
Click Here |
321 |
Create Maximum Number |
|
Click Here |
322 |
Coin Change |
|
Click Here |
323 |
Number of Connected Components... |
|
Click Here |
324 |
Wiggle Sort II |
|
Click Here |
325 |
Maximum Size Subarray Sum Equals k |
|
Not Buy |
326 |
Power of Three |
Math |
Click Here |
327 |
Count of Range Sum |
Divide |
Click Here |
328 |
Odd Even Linked List |
List |
Click Here |
329 |
Longest Increasing Path in a Matrix |
|
Click Here |
330 |
Patching Array |
|
Click Here |
331 |
Verify Preorder Serialization of a BTree |
|
Click Here |
332 |
Reconstruct Itinerary |
|
Click Here |
333 |
Largest BST Subtree |
|
Click Here |
334 |
Increasing Triplet Subsequence |
Array,DP |
Click Here |
335 |
Self Crossing |
|
Click Here |
336 |
Palindrome Pairs |
|
Click Here |
337 |
House Robber III |
|
Click Here |
338 |
Counting Bits |
DP,Bit |
Click Here |
339 |
Nested List Weight Sum |
|
Click Here |
340 |
Longest Substring with At Most K Distinct Characters |
|
Click Here |
341 |
Flatten Nested List Iterator |
|
Click Here |
342 |
Power of Four |
Math |
Click Here |
343 |
Integer Break |
Math |
Click Here |
344 |
Reverse String |
String |
Click Here |
345 |
Reverse Vowels of a String |
String,TP |
Click Here |
346 |
Moving Average from Data Stream |
Not Buy |
Not Buy |
347 |
Top K Frequent Elements |
Hash,Heap |
Click Here |
348 |
Design Tic-Tac-Toe |
Not Buy |
Not Buy |
349 |
Intersection of Two Arrays |
Hash,BS, |
Click Here |
350 |
Intersection of Two Arrays II |
TP,Hash |
Click Here |