# Problem Code Type Topic Companies Average Time Score
1 City Tour code Math
54:30 300
2 Excel Column Number code Math 23:12 175
3 Excel Column Title code Math 39:20 175
4 FizzBuzz code Math
12:07 200
5 Greatest Common Divisor code Math 10:53 200
6 Grid Unique Paths code Math 32:07 375
7 Largest Coprime Divisor code Math
44:31 250
8 Numbers of length N and value less than K code Math
79:27 200
9 Palindrome Integer code Math
HCL
17:23 200
10 Power Of Two Integers code Math 38:20 250
11 Prime Sum code Math 42:40 150
12 Rearrange Array code Math
48:18 250
13 Reverse integer code Math 27:59 200
14 Sorted Permutation Rank code Math 67:59 250
15 Sorted Permutation Rank with Repeats code Math 64:01 500
16 Sum of pairwise Hamming Distance code Math
58:25 200
17 Trailing Zeros in Factorial code Math 18:25 250
18 Arrange II code Dynamic Programming 70:04 350
19 Best Time to Buy and Sell Stocks I code Dynamic Programming 25:30 300
20 Best Time to Buy and Sell Stocks II code Dynamic Programming 35:28 225
21 Best Time to Buy and Sell Stocks III code Dynamic Programming 48:57 700
22 Coin Sum Infinite code Dynamic Programming
55:41 225
23 Coins in a Line code Dynamic Programming
51:29 300
24 Count Permutations of BST code Dynamic Programming
78:46 400
25 Distinct Subsequences code Dynamic Programming
52:00 325
26 Dungeon Princess code Dynamic Programming
57:31 300
27 Edit Distance code Dynamic Programming 41:19 300
28 Equal Average Partition code Dynamic Programming 84:12 350
29 Evaluate Expression To True code Dynamic Programming 66:09 350
30 Flip Array code Dynamic Programming
81:01 200
31 Interleaving Strings code Dynamic Programming
49:25 500
32 Intersecting Chords in a Circle code Dynamic Programming
58:14 300
33 Jump Game Array code Dynamic Programming 36:14 225
34 Kth Manhattan Distance Neighbourhood code Dynamic Programming 63:13 200
35 Largest area of rectangle with permutations code Dynamic Programming
60:58 200
36 Length of Longest Subsequence code Dynamic Programming
58:19 200
37 Longest Arithmetic Progression code Dynamic Programming
60:16 200
38 Longest Increasing Subsequence code Dynamic Programming 28:06 300
39 Longest valid Parentheses code Dynamic Programming
47:26 700
40 Max Product Subarray code Dynamic Programming 56:30 300
41 Max Rectangle in Binary Matrix code Dynamic Programming
64:38 350
42 Max Sum Path in Binary Tree code Dynamic Programming 47:14 400
43 Max Sum Without Adjacent Elements code Dynamic Programming 51:13 225
44 Min Jumps Array code Dynamic Programming 60:12 300
45 Min Sum Path in Matrix code Dynamic Programming 27:47 300
46 Min Sum Path in Triangle code Dynamic Programming
37:48 300
47 N digit numbers with digit sum S code Dynamic Programming
58:10 200
48 Palindrome Partitioning II code Dynamic Programming 47:57 400
49 Queen Attack code Dynamic Programming
74:24 350
50 Regular Expression II code Dynamic Programming
59:06 500
51 Regular Expression Match code Dynamic Programming
63:04 500
52 Repeating Sub-Sequence code Dynamic Programming
54:06 300
53 Rod Cutting code Dynamic Programming
76:20 350
54 Scramble String code Dynamic Programming
56:10 500
55 Shortest common superstring code Dynamic Programming
72:59 200
56 Stairs code Dynamic Programming 14:08 225
57 Sub Matrices with sum Zero code Dynamic Programming
73:28 200
58 Tushar's Birthday Bombs code Dynamic Programming
78:15 200
59 Tushar's Birthday Party code Dynamic Programming 59:58 200
60 Unique Binary Search Trees II code Dynamic Programming 30:12 400
61 Unique Paths in a Grid code Dynamic Programming
29:41 300
62 Ways to color a 3xN Board code Dynamic Programming 59:49 200
63 Ways to Decode code Dynamic Programming 62:39 225
64 Word Break code Dynamic Programming
IBM
51:17 400
65 Word Break II code Dynamic Programming
IBM
54:39 350
66 Add Two Numbers as Lists code Linked Lists 41:16 250
67 Insertion Sort List code Linked Lists
43:22 300
68 K reverse linked list code Linked Lists 52:13 200
69 List Cycle code Linked Lists 37:59 600
70 Merge Two Sorted Lists code Linked Lists 27:35 300
71 Palindrome List code Linked Lists 45:06 200
72 Partition List code Linked Lists
45:29 275
73 Remove Duplicates from Sorted List code Linked Lists 17:14 300
74 Remove Duplicates from Sorted List II code Linked Lists 52:55 300
75 Remove Nth Node from List End code Linked Lists 26:18 350
76 Reorder List code Linked Lists 53:18 600
77 Reverse Link List II code Linked Lists 55:19 450
78 Rotate List code Linked Lists 31:35 350
79 Sort List code Linked Lists
50:11 350
80 Swap List Nodes in pairs code Linked Lists 31:12 350
81 Actors and their Movies sql SQL Programming
23:59 100
82 Movie Character sql SQL Programming
24:02 100
83 Neutral Reviewers sql SQL Programming
19:45 100
84 Short Films sql SQL Programming
21:12 100
85 2-Sum Binary Tree code Tree Data Structure 55:11 400
86 Balanced Binary Tree code Tree Data Structure 28:41 275
87 Binary Tree From Inorder And Postorder code Tree Data Structure 41:39 375
88 BST Iterator code Tree Data Structure 35:38 500
89 Construct Binary Tree From Inorder And Preorder code Tree Data Structure 40:19 375
90 Flatten Binary Tree to Linked List code Tree Data Structure 39:14 500
91 Hotel Reviews code Tree Data Structure 64:17 200
92 Identical Binary Trees code Tree Data Structure 11:00 300
93 Inorder Traversal code Tree Data Structure 30:43 350
94 Inorder Traversal of Cartesian Tree code Tree Data Structure 43:39 300
95 Invert the Binary Tree code Tree Data Structure
12:00 300
96 Kth Smallest Element In Tree code Tree Data Structure 26:55 300
97 Least Common Ancestor code Tree Data Structure 53:02 450
98 Max Depth of Binary Tree code Tree Data Structure 6:32 350
99 Min Depth of Binary Tree code Tree Data Structure 16:17 350
100 Order of People Heights code Tree Data Structure
64:32 700
101 Path Sum code Tree Data Structure 25:22 350
102 Populate Next Right Pointers Tree code Tree Data Structure 44:51 900
103 Postorder Traversal code Tree Data Structure 28:31 350
104 Preorder Traversal code Tree Data Structure 14:13 350
105 Recover Binary Search Tree code Tree Data Structure
51:42 750
106 Root to Leaf Paths With Sum code Tree Data Structure 37:01 350
107 Shortest Unique Prefix code Tree Data Structure
62:23 350
108 Sorted Array To Balanced BST code Tree Data Structure 26:09 300
109 Sum Root to Leaf Numbers code Tree Data Structure
41:09 350
110 Symmetric Binary Tree code Tree Data Structure 20:15 300
111 Vertical Order traversal of Binary Tree code Tree Data Structure 64:45 200
112 ZigZag Level Order Traversal BT code Tree Data Structure 39:04 350
113 Add One To Number code Arrays
43:43 225
114 Anti Diagonals code Arrays 39:45 225
115 Find Duplicate in Array code Arrays 39:47 450
116 Find Permutation code Arrays
49:16 300
117 First Missing Integer code Arrays 64:02 300
118 Flip code Arrays 73:58 400
119 Hotel Bookings Possible code Arrays 61:55 225
120 Kth Row of Pascal's Triangle code Arrays
27:58 225
121 Largest Number code Arrays 70:21 225
122 Max Distance code Arrays 64:21 250
123 Max Non Negative SubArray code Arrays
57:45 150
124 Max Sum Contiguous Subarray code Arrays 33:39 225
125 Maximum Absolute Difference code Arrays
64:18 250
126 Maximum Consecutive Gap code Arrays 52:11 450
127 Maximum Unsorted Subarray code Arrays
59:06 250
128 MAXSPPROD code Arrays
74:21 200
129 Merge Intervals code Arrays
77:59 225
130 Merge Overlapping Intervals code Arrays 46:06 225
131 Min Steps in Infinite Grid code Arrays 37:51 150
132 N/3 Repeat Number code Arrays
63:18 600
133 Next Permutation code Arrays 58:43 300
134 Noble Integer code Arrays
42:18 200
135 Pascal Triangle code Arrays 26:29 225
136 Repeat and Missing Number Array code Arrays 63:22 350
137 Rotate Matrix code Arrays 58:32 300
138 Set Matrix Zeros code Arrays 47:08 300
139 Spiral Order Matrix II code Arrays 46:39 225
140 Triplets with Sum between given range code Arrays
69:58 200
141 Wave Array code Arrays 22:08 225
142 Convert Integer To Roman Number shell Regex and Functions
22:28 400
143 Sort by Frequency shell Regex and Functions
41:57 250
144 Swap Forward And Backward Slash shell Regex and Functions
14:50 200
145 Valid Email Address shell Regex and Functions
33:01 350
146 100 People in a Circle objective Puzzles
11:09 40
147 Ants on a Triangle objective Puzzles
4:41 40
148 Arrange Cubes objective Puzzles
15:05 40
149 Bee Travel objective Puzzles
7:50 40
150 Blindfolded Coin Toss objective Puzzles
3:10 40
151 Breaking Chocolate Bars objective Puzzles
5:02 40
152 Cats and a Square objective Puzzles
7:09 40
153 Celebrity Problem objective Puzzles
8:08 40
154 Color of the Bear objective Puzzles
3:26 40
155 Color of the last ball objective Puzzles
4:57 40
156 Color of the last ball II objective Puzzles
3:11 40
157 Cross the Bridge objective Puzzles
8:27 40
158 Cross the Bridge II objective Puzzles
5:21 40
159 Daughters' Ages objective Puzzles
12:02 40
160 Dinner Hand Shakes objective Puzzles
6:49 40
161 Divide Gold Bar objective Puzzles 5:38 40
162 Divide the Cake objective Puzzles
2:56 40
163 Eggs and Building objective Puzzles 12:22 40
164 Equilateral Triangles using Toothpicks objective Puzzles
5:45 40
165 Fake Note objective Puzzles
5:06 40
166 Fastest Horses objective Puzzles
6:45 40
167 Find the Defective Ball objective Puzzles
6:06 40
168 Find the Defective Ball II objective Puzzles
2:51 40
169 Gates of Heaven objective Puzzles
7:35 40
170 Genie and Hats objective Puzzles
7:05 40
171 Good Processor objective Puzzles
7:32 40
172 Helium Balloon objective Puzzles
1:53 40
173 Jelly Beans Jars objective Puzzles
7:05 40
174 Last Palindromic Date objective Puzzles
10:29 40
175 Light Switches in the Cellar objective Puzzles 2:51 40
176 Make a Statement objective Puzzles 4:11 40
177 Marbles in Jar objective Puzzles
10:23 40
178 Measure Milk by Cans objective Puzzles 14:09 40
179 Measure Time by Burning Ropes objective Puzzles
6:30 40
180 Measure Time by Hourglass objective Puzzles
8:36 40
181 Medicine Chest on a Boat objective Puzzles
8:38 40
182 Min Elevator Trips objective Puzzles
18:55 40
183 Monkeys and Doors objective Puzzles 10:27 40
184 Next Number objective Puzzles
16:53 40
185 Next Number II objective Puzzles 3:03 40
186 One Mile on the Globe objective Puzzles
7:23 40
187 Prisoners and Poison objective Puzzles 16:06 40
188 Quarters on a Table objective Puzzles
4:43 40
189 Ratio of Boys and Girls objective Puzzles
14:06 40
190 Six Colored Cubes objective Puzzles
12:24 40
191 Spider's Web objective Puzzles 3:35 40
192 Spinning Disc's Direction objective Puzzles
6:23 40
193 Ten Black and White Socks objective Puzzles
4:05 40
194 The Tribe objective Puzzles 5:53 40
195 Train Station objective Puzzles
17:25 40
196 Two Numbers objective Puzzles
11:35 40
197 Two Pills each day objective Puzzles
3:21 40
198 Wizards and Drawves objective Puzzles
12:20 40
199 World Trips objective Puzzles
9:01 40
200 3 Sum code Two Pointers 56:13 225
201 3 Sum Zero code Two Pointers
49:17 225
202 Array 3 Pointers code Two Pointers
48:07 400
203 Container With Most Water code Two Pointers 44:00 400
204 Counting Triangles code Two Pointers
51:41 225
205 Diffk code Two Pointers
27:27 300
206 Intersection Of Sorted Arrays code Two Pointers
17:46 225
207 Max Continuous Series of 1s code Two Pointers 69:52 300
208 Merge Two Sorted Lists II code Two Pointers 23:52 200
209 Minimize the absolute difference code Two Pointers
55:12 200
210 Remove Duplicates from Sorted Array code Two Pointers 30:14 250
211 Remove Duplicates from Sorted Array II code Two Pointers 30:25 250
212 Remove Element from Array code Two Pointers 26:18 250
213 Sort by Color code Two Pointers
21:32 325
214 Assign Mice to Holes code Greedy Algorithm 19:24 300
215 Bulbs code Greedy Algorithm
20:29 200
216 Distribute Candy code Greedy Algorithm 54:53 300
217 Gas Station code Greedy Algorithm 49:49 700
218 Highest Product code Greedy Algorithm 26:48 200
219 Majority Element code Greedy Algorithm
17:24 400
220 Seats code Greedy Algorithm 63:01 300
221 Distinct Numbers in Window code Heaps And Maps 35:51 600
222 LRU Cache code Heaps And Maps 64:09 1000
223 Magician and Chocolates code Heaps And Maps
37:36 250
224 Merge K Sorted Lists code Heaps And Maps 39:30 600
225 N max pair combinations code Heaps And Maps 71:44 200
226 Ways to form Max Heap code Heaps And Maps 72:45 200
227 Reverse Bits code Bit Manipulation 22:32 225
228 Number of 1 Bits code Bit Manipulation 8:35 200
229 Single Number code Bit Manipulation 11:36 275
230 Divide Integers code Bit Manipulation 57:08 250
231 Single Number II code Bit Manipulation 36:58 275
232 Different Bits Sum Pairwise code Bit Manipulation
45:21 300
233 Min XOR value code Bit Manipulation 35:59 200
234 2 Sum code Hashing 45:16 300
235 4 Sum code Hashing 57:49 325
236 Anagrams code Hashing 42:43 350
237 Colorful Number code Hashing 41:08 150
238 Copy List code Hashing 47:25 450
239 Diffk II code Hashing
26:24 375
240 Equal code Hashing
62:51 350
241 Fraction code Hashing 69:19 450
242 Largest Continuous Sequence Zero Sum code Hashing
59:28 200
243 Longest Substring Without Repeat code Hashing 45:43 350
244 Points on the Straight Line code Hashing 64:52 450
245 Substring Concatenation code Hashing
64:09 1000
246 Valid Sudoku code Hashing 43:31 325
247 Window String code Hashing 68:37 350
248 Lines in a given range shell Basic Shell Commands
31:04 200
249 Remove Punctuations shell Basic Shell Commands
14:33 250
250 Transform CSV shell Basic Shell Commands
23:44 300
251 Valid phone number shell Basic Shell Commands
22:34 150
252 AMORTIZED1 objective Time Complexity
3:03 100
253 CHOOSE1 objective Time Complexity
1:43 50
254 CHOOSE2 objective Time Complexity
2:23 80
255 CHOOSE3 objective Time Complexity
1:39 50
256 CHOOSE4 objective Time Complexity
0:57 50
257 GCD_CMPL objective Time Complexity
4:13 150
258 LOOP_CMPL objective Time Complexity
2:43 20
259 LOOP_CMPL2 objective Time Complexity
2:43 80
260 NESTED_CMPL objective Time Complexity
1:10 20
261 NESTED_CMPL2 objective Time Complexity
1:25 30
262 NESTED_CMPL3 objective Time Complexity
3:56 80
263 REC_CMPL1 objective Time Complexity
6:58 80
264 REC_CMPL2 objective Time Complexity
6:25 80
265 REC_CMPL3 objective Time Complexity
4:39 150
266 WHILE_CMPL objective Time Complexity
1:31 50
267 Design Cache subjective Storage Scalability 40:00 200
268 Highly Available Database subjective Storage Scalability 50:00 400
269 Highly Consistent Database subjective Storage Scalability
50:00 400
270 Sharding a Database subjective Storage Scalability 35:00 200
271 Another chocolate game code Codersbit
39:29 200
272 Array and Prime Divisors code Codersbit
27:16 150
273 Delete and Conquer code Codersbit
10:15 150
274 Distinct Primes code Codersbit
57:16 150
275 EZPZ code Codersbit
37:38 200
276 Going back to OS objective Codersbit
15:00 30
277 Longest Subarray Difference code Codersbit
67:23 200
278 MinimiZe code Codersbit
33:42 200
279 Prime Subarrays code Codersbit
27:58 150
280 Scores code Codersbit
76:45 200
281 Shortest Path in Simple Graph objective Codersbit
3:59 30
282 Simple Queries code Codersbit
64:35 300
283 Smallest Subarray code Codersbit
34:55 250
284 The Sequence game code Codersbit
26:59 200
285 The square game code Codersbit
6:48 200
286 Three Numbers code Codersbit
47:12 200
287 Try some SQL objective Codersbit
10:07 30
288 Very Hard Queries code Codersbit
75:36 200
289 Vowels code Codersbit
57:49 250
290 Design Messenger subjective System Design Interview Questions 41:40 600
291 Design Search Typeahead subjective System Design Interview Questions
53:20 400
292 Design Twitter subjective System Design Interview Questions 38:20 600
293 Design URL Shortener subjective System Design Interview Questions 45:00 300
294 Evaluate Expression code Stacks And Queues
31:24 400
295 Largest Rectangle in Histogram code Stacks And Queues
58:08 450
296 Min Stack code Stacks And Queues 41:01 400
297 Nearest Smaller Element code Stacks And Queues 40:02 350
298 Rain Water Trapped code Stacks And Queues 53:01 400
299 Redundant Braces code Stacks And Queues 40:29 300
300 Simplify Directory Path code Stacks And Queues
49:14 250
301 Sliding Window Maximum code Stacks And Queues 60:54 450
302 Add Binary Strings code Strings
38:00 300
303 Amazing Subarrays code Strings
20:14 150
304 Atoi code Strings 49:25 250
305 Compare Version Numbers code Strings 60:19 225
306 Count And Say code Strings
40:16 250
307 Implement StrStr code Strings 32:11 225
308 Integer To Roman code Strings 37:58 250
309 Justified Text code Strings
68:34 300
310 Length of Last Word code Strings 17:48 225
311 Longest Common Prefix code Strings
26:48 225
312 Longest Palindromic Substring code Strings 55:21 500
313 Minimum Characters required to make a String Palindromic code Strings
58:04 200
314 Multiply Strings code Strings
55:44 375
315 Palindrome String code Strings
30:19 150
316 Power of 2 code Strings 55:59 350
317 Pretty Json code Strings
55:43 400
318 Reverse the String code Strings 35:55 250
319 Roman To Integer code Strings 31:21 250
320 Stringoholics code Strings
68:19 300
321 Valid Ip Addresses code Strings 54:52 250
322 Valid Number code Strings 52:45 250
323 Zigzag String code Strings
48:34 300
324 Combination Sum code Backtracking 54:26 300
325 Combination Sum II code Backtracking 36:24 300
326 Combinations code Backtracking 40:41 300
327 Generate all Parentheses II code Backtracking
46:20 350
328 Gray Code code Backtracking
51:20 350
329 Kth Permutation Sequence code Backtracking 68:29 350
330 Letter Phone code Backtracking 48:24 250
331 NQueens code Backtracking 65:19 550
332 Palindrome Partitioning code Backtracking 59:37 300
333 Permutations code Backtracking 35:47 350
334 Subset code Backtracking 55:51 250
335 Subsets II code Backtracking 35:20 300
336 Sudoku code Backtracking 55:56 700
337 Black Shapes code Graph Data Structure & Algorithms 43:07 300
338 Capture Regions on Board code Graph Data Structure & Algorithms
53:27 500
339 Clone Graph code Graph Data Structure & Algorithms 47:19 500
340 Commutable Islands code Graph Data Structure & Algorithms 60:27 200
341 Convert Sorted List to Binary Search Tree code Graph Data Structure & Algorithms
37:01 300
342 Knight On Chess Board code Graph Data Structure & Algorithms 54:54 300
343 Largest Distance between nodes of a Tree code Graph Data Structure & Algorithms
65:35 200
344 Level Order code Graph Data Structure & Algorithms 26:36 300
345 Possibility of finishing all courses given pre-requisites code Graph Data Structure & Algorithms 52:20 200
346 Smallest Multiple With 0 and 1 code Graph Data Structure & Algorithms 75:29 300
347 Smallest sequence with given Primes code Graph Data Structure & Algorithms 52:41 200
348 Stepping Numbers code Graph Data Structure & Algorithms 46:31 300
349 Sum Of Fibonacci Numbers code Graph Data Structure & Algorithms
44:16 300
350 Valid Path code Graph Data Structure & Algorithms 75:37 200
351 Word Ladder I code Graph Data Structure & Algorithms 53:04 600
352 Word Ladder II code Graph Data Structure & Algorithms 63:54 800
353 Word Search Board code Graph Data Structure & Algorithms 44:28 500
354 Allocate Books code Binary Search
58:38 350
355 Implement Power Function code Binary Search
57:43 275
356 Matrix Median code Binary Search
64:21 225
357 Matrix Search code Binary Search
35:17 250
358 Median of Array code Binary Search 71:07 325
359 Painter's Partition Problem code Binary Search
68:54 350
360 Rotated Sorted Array Search code Binary Search 54:28 325
361 Search for a Range code Binary Search
40:11 250
362 Sorted Insert Position code Binary Search
23:47 250
363 Square Root of Integer code Binary Search 40:14 275