abigcleverdog / LeetCode

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Overview

Starting 12/06/2017, a diary for solving LeetCode problems.
2018/1/16 strategy change, focus on the 1-400; round 1
2018/4/9 finished round 1 with python, skipped some problems, such as tricky dp or indiced tree etc and the paid problems.
2018/4/10 round 2 with java.

LC contests Week rank result
24 8/11/2018 667 / 3760 2/4; 8/22
23 8/04/2018 563 / 4703 2/4; 9/22
22 7/28/2018 1155 / 4580 2/4; 8/22
21 7/21/2018 547 / 4542 2/4; 10/20
20 7/14/2018 687 / 4912 3/4; 15/24
19 7/07/2018 445 / 3650 2/4; 7/23
18 6/30/2018 493 / 3650 2/4; 8/25
17 6/23/2018 409 / 4410 3/4; 15/24
16 6/16/2018 420 / 3646 2/4; 8/24
15 6/09/2018 571 / 3407 2/4; 8/21
14 6/02/2018 356 / 3029 3/4; 13/21
13 5/26/2018 1031 / 2697 1/4; 5/22
12 5/19/2018 287 / 2997 2/4; 9/26
11 5/12/2018 605 / 3076 2/4; 7/22
10 5/05/2018 275 / 2743 3/4; 15/24
9 4/28/2018 332 / 2563 3/4; 16/24
8 4/21/2018 341 / 2797 3/4; 15/22
7 4/14/2018 132 / 2570 3/4; 14/22
6 4/07/2018 161 / 2485 3/4; 16/22
5 3/31/2018 894 / 3074 1/4; 5/26
4 3/24/2018 460 / 2982 3/4; 13/22
3 3/17/2018 414 / 2849 1/4; 4/28
2 3/10/2018 516 / 2830 2/4; 8/22
1 3/03/2018 490 / 2674 2/4; 14/28
25 8/18/2018 387 / 3552 3/4; 13/20
26 8/25/2018 534 / 3877 3/4; 14/20
27 9/01/2018 1165/ 4008 2/4; 5/18
28 9/08/2018 413/ 4937 2/4; 8/24
29 9/15/2018 349/ 4385 3/4; 13/20
30 9/22/2018 361/ 4160 2/4; 9/21
31 9/29/2018 335/ 3579 3/4; 14/22
32 10/06/2018 1387/ 3528 1/4; 4/25
33 10/13/2018 1251/ 3068 2/4; 7/20
34 10/20/2018 462/ 3711 3/4; 17/25
35 10/27/2018 582/ 3652 3/4; 14/20
36 11/03/2018 1056/2948 1/4; 4/23
37 11/10/2018 798/ 3720 3/4; 13/20
38 11/17/2018 256/ 3587 3/4; 12/20
39 11/24/2018 636/ 3194 3/4; 17/23
40 12/01/2018 269/ 3549 3/4; 14/22
41 12/08/2018 303/ 3198 3/4; 15/23
42 12/15/2018 252/ 3055 2/4; 12/25
43 12/22/2018 278/ 2965 3/4; 12/21
44 12/29/2018 430/ 3425 3/4; 14/22

Round 2 stack:
can do:

  • 12/29   *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (6) Q4 (8)
    430 / 3425 abigcleverdog 14 1:14:11 0:06:23 0:31:37 2 1:04:11

  • 12/22   *****
    Rank Name Score Finish Time Q1 (2) Q2 (5) Q3 (5) Q4 (9)
    278 / 2965 abigcleverdog 12 1:40:21 0:10:50 1 0:28:20 1:20:21 3

  • 12/15   *****
    Rank Name Score Finish Time Q1 (5) Q2 (6) Q3 (7) Q4 (7)
    252 / 3055 abigcleverdog 12 1:37:14 0:19:23 1 1:27:14 1


  • 12/09 *****
    rp: 316
    jp: 316

  • 12/08   *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (8)
    302 / 3198 abigcleverdog 15 1:15:53 0:12:01 0:35:33 1:05:53 2

  • 12/01   *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (5) Q4 (8)
    269 / 3549 abigcleverdog 14 0:42:21 0:22:54 0:27:17 0:42:21

  • 11/24   *****
    Rank Name Score Finish Time Q1 (5) Q2 (6) Q3 (6) Q4 (6)
    636 / 3194 abigcleverdog 17 1:38:39 0:08:24 0:42:34 2 1:28:39

  • 11/25 *****
    rp: 279
    jp: 307

  • 11/17   *****
    Rank Name Score Finish Time Q1 (3) Q2 (4) Q3 (5) Q4 (8)
    256 / 3587 abigcleverdog 12 0:23:52 0:07:01 0:17:25 0:23:52

  • 11/11 *****
    rp: 264
    jp: 307

  • 11/10   *****
    Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (5) Q4 (7)
    798 / 3720 abigcleverdog 13 1:35:41 0:19:42 0:27:36 1:25:41 2

  • 11/03 *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (8)
    1056 / 2948 abigcleverdog 4 0:04:47 0:04:47

  • 11/02   *****
    rp: 264
    jp: 264

  • 10/27 *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (5) Q4 (6)
    582 / 3652 abigcleverdog 14 1:01:15 0:11:32 0:47:35 1 0:56:15

  • 10/26   *****
    rp: 222
    jp: 264

  • 10/25 *****
    rp: 216
    jp: 264

  • 10/20 *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (8) Q4 (8)
    462 / 3711 abigcleverdog 17 1:36:23 0:09:20 1 0:19:39 1:16:23 3

  • 10/16   *****
    rp: 216
    jp: 216

  • 10/13 *****
    Rank Name Score Finish Time Q1 (3) Q2 (4) Q3 (6) Q4 (7)
    1251 / 3068 abigcleverdog 7 0:16:24 0:11:41 0:16:24

  • 10/06 *****
    Rank Name Score Finish Time Q1 (4) Q2 (6) Q3 (7) Q4 (8)
    1387 / 3528 abigcleverdog 4 0:08:56 0:08:56

  • 9/29 *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (6) Q4 (8)
    335 / 3579 abigcleverdog 14 0:46:25 0:27:15 1 0:08:31 0:41:25

  • 9/22 *****
    Rank Name Score Finish Time Q1 (3) Q2 (6) Q3 (6) Q4 (6)
    361 / 4160 abigcleverdog 9 1:04:03 0:07:12 0:59:03 1

  • 7/17   *****
    rp: 150
    jp: 216

  • 9/15 *****
    Rank Name Score Finish Time Q1 (2) Q2 (5) Q3 (6) Q4 (7)
    349 / 4385 abigcleverdog 13 1:25:27 0:07:12 0:43:30 1 1:15:27 1

  • 9/8 *****
    Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (7) Q4 (9)
    413 / 4937 abigcleverdog 8 0:35:14 0:35:14 0:23:59

  • 9/1   *****
    Rank Name Score Finish Time Q1 (2) Q2 (3) Q3 (6) Q4 (7)
    1165 / 4008 abigcleverdog 5 0:39:54 0:10:03 0:34:54 1

  • 8/25   *****
    Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (6) Q4 (8)
    534 / 3877 abigcleverdog 14 1:24:58 0:18:20 1:19:58 1 0:56:38

  • 8/18   *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (5) Q4 (7)
    387 / 3552 abigcleverdog 13 0:52:51 0:19:40 0:31:25 0:52:51

  • 8/11   *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (5) Q4 (9)
    667 / 3760 abigcleverdog 8 0:45:19 0:10:50 0:45:19

  • 8/7   *****
    rp: 150
    jp: 150

  • 8/6   *****
    rp: 144
    jp: 150

  • 8/4   *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (7)
    563 / 4703 abigcleverdog 9 0:27:22 0:20:12 0:27:22

  • 8/1   *****
    rp: 130
    jp: 150

  • 7/31   *****
    rp: 125
    jp: 150

  • 7/29   *****
    rp: 120
    jp: 150

  • 7/28   *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (7) Q4 (7)
    1155 / 4580 abigcleverdog 8 1:10:12 0:03:09 1:05:12 1

  • 7/27   *****
    rp: 100
    jp: 148

  • 7/26   *****
    rp: 100
    jp: 142

  • 7/25   *****
    rp: 100
    jp: 133

  • 7/24   *****
    rp: 100
    jp: 130

  • 7/21   *****
    Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (6) Q4 (6)
    547 / 4542 abigcleverdog 10 0:49:14 0:18:36 0:49:14

  • 7/16   *****
    rp: 100
    jp: 128

  • 7/16   *****
    rp: 100
    jp: 125  

  • 7/14   *****
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (7) Q4 (9)
    687 / 4912 abigcleverdog 15 1:20:56 0:10:21 0:34:57 1:05:56 3

  • 7/13   *****
    rp: 100
    jp: 123  

  • 7/12   *****
    rp: 100
    jp: 113  

  • 7/11   *****
    rp: 100
    jp: 105  

  • 7/10   *****
    rp: 99
    jp: 100  

  • 7/8   *****
    rp: 90
    jp: 100  

  • 7/7   *****
    Rank Name Score Finish Time Q1 (2) Q2 (5) Q3 (7) Q4 (9)
    445 / 4508 abigcleverdog 7 0:14:55 0:04:13 0:14:55

  • 7/6   *****
    rp: 86
    jp: 100  

  • 7/5   *****
    rp: 83
    jp: 100  

  • 7/1   *****
    rp: 77
    jp: 100  

  • 6/30   *****
    Rank Name Score Finish Time Q1 (2) Q2 (6) Q3 (6) Q4 (11)
    493 / 3650 abigcleverdog 8 0:34:54 0:08:29 0:34:54

  • 6/27   *****
    rp: 68
    jp: 100  

  • 6/26   *****
    rp: 64
    jp: 100  

  • 6/25   *****
    rp: 57
    jp: 100  

  • 6/23   *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (9)
    409 / 4410 abigcleverdog 15 1:47:12 0:13:11 2 0:21:43 1 1:12:12 4

  • 6/18   *****
    rp: 50
    jp: 98  

  • 6/16   *****
    Rank Name Score Finish Time Q1 (2) Q2 (6) Q3 (6) Q4 (10)
    420 / 3646 abigcleverdog 8 0:44:21 0:09:47 0:39:21 1

  • 6/11   *****
    rp: 50
    jp: 91  

  • 6/9   *****
    Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (5) Q4 (8)
    571 / 3407 abigcleverdog 8 0:28:30 0:14:44 0:28:30

  • 6/7   *****
    rp: 50
    jp: 86  

  • 6/2   ***** Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (5) Q4 (8)
    356 / 3029 abigcleverdog 13 0:58:20 0:12:52 1 0:19:30 2 0:43:20

  • 5/26   ***** computer crushed :(
    Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (6) Q4 (8)
    1031 / 2697 abigcleverdog 5 0:38:37 0:38:37

  • 5/25   *****
    rp: 50
    jp: 75  

  • 5/24   *****
    rp: 50
    jp: 72  

  • 5/23   *****
    rp: 50
    jp: 67  

  • 5/22   *****
    rp: 50
    jp: 62  

  • 5/19   *****
    Rank Name Score Finish Time Q1 (3) Q2 (6) Q3 (7) Q4 (10) 287 / 2997 abigcleverdog 9 0:40:16 0:07:31 0:35:16 1

  • 5/18   *****
    rp: 50
    jp: 55  

  • 5/17 *****
    rp: 50
    jp: 53

  • 5/15 *****
    rp: 50
    jp: 51

  • 5/12 *****
    Rank Name Score Finish Time Q1 (3) Q2 (4) Q3 (6) Q4 (9)
    602 / 3076 abigcleverdog 7 0:47:02 0:06:29 0:47:02

  • 5/10 *****
    rp: 47
    jp: 50

  • 5/9 *****
    rp: 43
    jp: 50

  • 5/8 *****
    rp: 36
    jp: 50

  • 5/7 *****
    rp: 34
    jp: 50

  • 5/6 *****
    for problem 30. stucked at the two pointers. the problem was == vs. .equals; when I built the String[] for two pointers, the Strings in the array are objects so "foo" @ idx 2 != "foo" @ idx 3, but "foo"@2 .equals "foo"@3
    rp: 30
    jp: 50

  • 5/5 ***** Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (7) Q4 (9)
    275 / 2743 abigcleverdog 15 0:54:46 0:09:59 1 0:49:46 0:30:00

  • 5/4 *****
    rp: 28
    jp: 50

  • 5/3 *****
    rp: 22
    jp: 50

  • 5/2 *****
    print simple array: Arrays.toString(arr);
    print nested array: Arrays.deepToString(arr); rp: 17
    jp: 50

  • 5/1 *****
    rp: 6
    jp: 50

  • 4/30 *****
    int to String:
    int i = 1;
  1. i + ""; --> "1"
  2. String.valueOf(i); --> "1"
  3. Integer.toString(i); --> "1"

Integer i = 1;

  1. i.toString(); --> "1" * be careful of nullpointerexception
  2. String.valueOf(i); "1" * will be "null" if i is null

String to int:
String s = "1";

  1. Integer.valueOf(s); --> 1 * boxed integer object  
  2. Integer.parseInt(s); --> 1 * primative int

Integer auto cache: -128 ~ 127

rp: 3
jp: 50


  • 4/29 *****
    rp: 41
    jp: 50

  • 4/28 *****
    Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (7) Q4 (8)
    332 / 2563 abigcleverdog 16 1:24:12 0:08:34 1:14:12 2 1:00:15
    rp: 41
    jp: 45

  • 4/27 *****
    rp: 41
    jp: 43

  • 4/26 *****
    convert an int to string: int.toString() doesn't work as int is a primative type, not an object, so no method associates with it; have to do Integer.toString(int), Integer is an object.
    int + char1 will return a char2 whose ascii is greater than char1 by int
    an obj i.e. TreeNode can be compared to another TreeNode when we implement the comparable interface; however we can compare two TreeNode references if they are pointing to the same TreeNode (TreeNode a == TreeNode b).
    rp: 41
    jp: 41

  • 4/25 *****
    notated someone's 37 Sudoku Solver 2ms solution
    rp: 37
    jp: 41

  • 4/24 *****
    PriorityQueue offer, peek, poll; Comparable vs. Comparator.
    Deque for Stack; push(e), pop(), peek() (throw exceptions)
    rp: 35
    jp: 41

  • 4/23 *****
    1<<31 = -2147483648 (*return an int); 1L<<31 or (long) 1<<31 = 2147483648 (*return a long)
    Arrays.toString(arr) or Arrays.deepToString(arr) for arrays within arrays.
    rp: 33
    jp: 41

  • 4/21 ***** Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (7) 340 / 2797 abigcleverdog 15 0:43:28 0:43:28 0:29:10 0:17:41

  • 4/19 ***** rp: 20 jp: 41

  • 4/16 ***** rp: 20 jp:

  • 4/14 ***** Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (6) Q4 (8) 132 / 2570 abigcleverdog 14 0:48:37 0:12:04 0:20:49 1 0:43:37

  • 4/13 ***** it has been a little messy. so I guess just check in the progress daily for now. review progress: 20; java progress: 29


  • 4/10 (6, 338) ***** 1, 2, 3, 5, 6

  • 4/9 (6, 338) *****
  1. 394 Decode String
  2. 395 Longest Substring with At Least K Repeating Characters
  3. 396 Rotate Function
  4. 397 Integer Replacement
  5. 398 Random Pick Index
  6. 399 Evaluate Division

  • 4/8 (2, 332) *****
  1. 392 Is Subsequence
  2. 393 UTF-8 Validation

  • 4/7 (2, 330) ***** Rank Name Score Finish Time Q1 (4) Q2 (5) Q3 (6) Q4 (7) 161 / 2485 abigcleverdog 16 1:10:16 0:49:07 0:18:16 1:10:16
  1. 390 Elimination Game
  2. 391 Perfect Rectangle

  • 4/6 (6, 328) *****
  1. 378 Kth Smallest Element in a Sorted Matrix
  2. 380 Insert Delete GetRandom O(1)
  3. 381 Insert Delete GetRandom O(1) - Duplicates allowed
  4. 385 Mini Parser
  5. 386 Lexicographical Numbers
  6. 388 Longest Absolute File Path

  • 4/5 (5, 322) *****
  1. 372 Super Pow
  2. 373 Find K Pairs with Smallest Sums
  3. 375 Guess Number Higher or Lower II
  4. 376 Wiggle Subsequence
  5. 377 Combination Sum IV

  • 4/4 (3, 317) *****
  1. 363 Max Sum of Rectangle No Larger Than K -- not done
  2. 365 Water and Jug Problem
  3. 368 Largest Divisible Subset

  • 4/3 (6, 314) *****
  1. 341 Flatten Nested List Iterator
  2. 343 Integer Break
  3. 352 Data Stream as Disjoint Intervals
  4. 354 Russian Doll Envelopes
  5. 355 Design Twitter
  6. 357 Count Numbers with Unique Digits

  • 4/2 (3, 308) *****
  1. 335 Self Crossing
  2. 336 Palindrome Pairs
  3. 337 House Robber III

  • 3/31 (0, 305) ***** Rank Name Score Finish Time Q1 (5) Q2 (5) Q3 (7) Q4 (9) 894 / 3074 abigcleverdog 5 0:21:28 0:21:28

  • 3/24 (0, 305) ***** Rank Name Score Finish Time Q1 (4) Q2 (4) Q3 (5) Q4 (9) 460 / 2982 abigcleverdog 13 0:28:36 0:10:05 0:14:51 0:28:36

  • 3/23 (3, 305) *****
  1. 331 Verify Preorder Serialization of a Binary Tree
  2. 332 Reconstruct Itinerary
  3. 334 Increasing Triplet Subsequence

  • 3/22 (3, 305) *****
  1. 327 Count Range Sum -- not done
  2. 328 Odd Even Linked List
  3. 329 Longest Increasing Path in a Matrix
  4. 330 Patching Array

  • 3/21 (4, 302) *****
  1. 316 Remove Duplicate Letters -- not done
  2. 318 Maximum Product of Word Lengths
  3. 319 Bulb Switcher
  4. 321 Create Maximum Number -- not done
  5. 322 Coin Change
  6. 324 Wiggle Sort II

  • 3/20 (1, 298) *****
  1. 312 Burst Balloons -- not done
  2. 313 Super Ugly Number
  3. 315 Count of Smaller numbers After Self -- not done

  • 3/19 (1, 297) *****
  1. 310 Minimum Height Trees

  • 3/18 (1, 296) *****
  1. 309 Best Time to Buy and Sell Stock with Cooldown -- not done

  • 3/17 (3, 296) *****
  1. 304 Range Sum Query 2D - Immutable
  2. 306 Additive Number
  3. 307 Range Sum Query - Mutable -- not done Rank Name Score Finish Time Q1 (4) Q2 (6) Q3 (7) Q4 (11) 414 / 2849 abigcleverdog 4 0:29:40 0:24:40 1

  • 3/16 (4, 294) *****
  1. 297 Serialize and Deserialize Binary Tree
  2. 299 Bulls and Cows
  3. 300 Longest Increasing Subsequence
  4. 301 Remove Invalid Parentheses

  • 3/15 (4, 290) *****
  1. 284 Peeking Iterator
  2. 287 Find the Duplicate Number
  3. 289 Game of Life
  4. 295 Find Median from Data Stream

  • 3/15 (0, 286) *****
  1. 284 Peeking Iterator

  • 3/14 (1, 286) *****
  1. 282 Expression Add Operators

  • 3/13 (1, 285) *****
  1. 279 Perfect Squares

  • 3/12 (1, 284) *****
  1. 275 H-Index II

  • 3/10 (1, 283) *****
  1. 274 H-Index

Rank Name Score Finish Time Q1 (3) Q2 (5) Q3 (7) Q4 (7) 516 / 2830 abigcleverdog 8 0:16:06 0:05:01 0:16:06


  • 3/9 (1, 282) *****
  1. 264 Ugly Number II

  • 3/8 (2, 281) *****
  1. 240 Search a 2D Matrix II
  2. 241 Different Ways to Add Parentheses

  • 3/7 (2, 279) *****
  1. 236 Lowest Common Ancestor of a Binary Tree
  2. 239 Sliding Window Maximum

  • 3/4 (3, 277) *****
  1. 228 Contains Duplicate III
  2. 229 Majority Element II
  3. 230 Kth Smallest Element in a BST
  4. 233 Number of Digit One --- not done
  • 3/3 Rank Name Score Finish Time Q1 (7) Q2 (7) Q3 (7) Q4 (7) 490 / 2674 abigcleverdog 14 1:25:34 0:29:17 1 1:10:34 2 huge room for improvement...

  • 3/2 (6, 274) *****
  1. 220 Contains Duplicate III
  2. 221 Maximal Square
  3. 222 Count Complete Tree Nodes
  4. 223 Rectangle Area
  5. 224 Basic Calculator
  6. 227 Basic Calculator II

  • 3/1 (5, 268) *****
  1. 212 Word Search II
  2. 213 House Robber II
  3. 214 Shortest Palindrome
  4. 215 Kth Largest Element in an Array
  5. 216 Combination Sum III
  6. 218 The Skyline Problem --not done

  • 2/28 (2, 263) *****
  1. 210 Course Schedule II
  2. 211 Add and Search Word - Data structure design

  • 2/27 (8, 261) *****
  1. 179 Largest Number
  2. 187 Repeated DNA Sequences
  3. 188 Best Time to Buy and Sell Stock IV -- not done
  4. 199 Binary Tree Right Side View
  5. 200 Number of Islands
  6. 201 Bitwise AND of Numbers Range
  7. 207 Course Schedule
  8. 208 Implement Trie (Prefix Tree)
  9. 209 Minimum Size Subarray Sum

  • 2/26 (8, 253) *****
  1. 153 Find Minimum in Rotated Sorted Array
  2. 154 Find Minimum in Rotated Sorted Array II
  3. 162 Find Peak Element
  4. 164 Maximum Gap
  5. 165 Compare Version Numbers
  6. 166 Fraction to Recurring Decimal
  7. 173 Binary Search Trea Iterator
  8. 174 Dungeon Game

  • 2/25 (3, 245) *****
  1. 150 Evaluate Reverse Polish Notation
  2. 151 Reverse Words in a String
  3. 152 Maximum Product Subarray

  • 2/24 (2, 242) *****
  1. 148 Sort List
  2. 149 Max Points on a Line

  • 2/23 (6, 240) *****
  1. 142 Linked List Cycle II
  2. 143 Reorder List
  3. 144 Binary Tree Preorder Traversal
  4. 145 Binary Tree Postorder Traversal
  5. 146 LRU Cache
  6. 147 Insertion Sort List

  • 2/22 (3, 234) *****
  1. 137 Single Number II
  2. 139 Word Break
  3. 140 Word Break II

  • 2/21 (5, 231) *****
  1. 132 Palindrome Partitioning II
  2. 133 Clone Graph
  3. 134 Gas Station
  4. 135 Candy
  5. 137 Single Number II -- not done
  6. 138 Copy List with Random Pointer

  • 2/20 (6, 226) *****
  1. 123 Best Time to Buy and Sell Stock III
  2. 124 Binary Tree Maximum Path Sum
  3. 126 Word Ladder II -- not accepted
  4. 128 Longest Consecutive Sequence
  5. 129 Sum Root to Leaf Numbers
  6. 130 Surrounded Regions
  7. 131 Palindrome Partitioning

  • 2/19 (6, 220) *****
  1. 105 Construct Binary Tree from Preorder and Inorder Traversal
  2. 106 Construct Binary Tree from Inorder and Postorder Traversal
  3. 115 Distinct Subsequences
  4. 117 Populating Next Right Pointers in Each Node II
  5. 120 Triangle
  6. 123 Best Time to Buy and Sell Stock III -- not done
  7. 127 Word Ladder

  • 2/18 (8, 214) ***** skip 105, 106
  1. 97 Interleaving String
  2. 98 Validate Binary Search Tree
  3. 99 Recover Binary Search Tree
  4. 102 Binary Tree Level Order Traversal
  5. 103 Binary Tree ZigZag Level Order Traversal
  6. 105 Construct Binary Tree from Preorder and Inorder Traversal -- not done
  7. 109 Convert Sorted List to Binary Search Tree
  8. 113 Path Sum II
  9. 114 Flatten Binary Tree to Linked List

  • 2/17 (1, 206) *****
  1. 96 Unique Binary Search Treas

  • 2/16 (4, 205) *****
  1. 85 Maximal Rectangle
  2. 87 Scramble String
  3. 89 Grey Code
  4. 95 Unique Binary Search Treas II

  • 2/15 (2, 201) *****
  1. skip 85, 87, 89 for now.
  2. 92 Reverse Linked List II
  3. 93 Restore IP Addresses

  • 2/13 (2, 199) *****
  1. skip 85, 87, 89 for now.
  2. 90 Subsets II
  3. 91 Decode Ways

  • 2/12 (1, 197) *****
  1. skip 85, 87 for now.
  2. 86 Partition List
  3. 89 Grey Code -- not done

  • 2/11 (0, 196) *****
  1. 84 Largest Rectangle in Histogram

  • 2/10 (1, 196) *****
  1. 84 Largest Rectangle in Histogram

  • 2/9 (2, 195) *****
  1. 81 Search in Rotated Sorted Array II
  2. 82 Remove Duplicates from Sorted List II
  3. 84 Largest Rectangle in Histogram ----- not done

  • 2/8 (2, 193) *****
  1. 79 Word Search
  2. 80 Remove Duplicates from Sorted Array II

  • 2/7 (2, 191) *****
  1. 76 Combinations
  2. 78 Subsets

  • 2/6 (1, 189) *****
  1. 77 Combinations

  • 2/5 (2, 188) *****
  1. 74 Search a 2D Matrix
  2. 75 Sort Colors
  3. 76 Minimum Window Substring --- not done

  • 2/4 (3, 186) *****
  1. 71 Simplify Path
  2. 72 Edit Distance
  3. 73 Set Matrix Zeroes

  • 2/3 (1, 183) *****
  1. 68 Text Justification

  • 2/2 Fri (5, 182) *****
  1. 60 Insert Interval
  2. 61 Rotate List
  3. 62 Unique Paths
  4. 63 Unique Paths II
  5. 64 Minimum Path Sum

  • 2/1 Thu (2, 177) *****
  1. 57 Insert Interval
  2. 59 Spiral Matrix II

  • 1/31 Wed (2, 175) *****
  1. 55 Jump Game
  2. 56 Merge Intervals

  • 1/30 Tue (1, 173) *****
  1. 54 Spiral Matrix

  • 1/29 Mon (1, 172) *****
  1. 52 N-Queens II

  • 1/28 Sun (4, 171) *****
  1. 48 Rotate Image
  2. 49 Group Anagrams
  3. 50 Pow(x, n)
  4. 51 N-Queens

  • 1/27 Sat (5, 167) *****
  1. 43 Multiply Strings
  2. 44 Wildcard Matching
  3. 45 Jump Game II
  4. 46 Pemutations
  5. 47 Pemutations II

  • 1/26 Fri (3, 162) *****
  1. 40 Combination Sum II
  2. 41 First Missing Positive
  3. 42 Trapping Rain Water

  • 1/25 Thu (1, 159) *****
  1. 39 Combination Sum

  • 1/24 Thu (1, 158) *****
  1. 37 Sudoku Solver

  • 1/23 Tue (3, 157) *****
  1. 32 Longest Valid Parentheses
  2. 33 Search in Rotated Sorted Array
  3. 34 Search for a Range

  • 1/22 Mon (2, 154) *****
  1. 31 Next Pemutation

  • 1/21 Sun (3, 152) *****
  1. 24 Swap Nodes in Pairs
  2. 25 Reverse Nodes in k-Group
  3. 29 Divide Two Integers
  4. 30 Substring with Concatenation of All Words

  • 1/20 Sat (4, 149) *****
  1. 17 Letter Combinations of a Phone Number
  2. 18 4Sum
  3. 19 Remove Nth Node From End of List
  4. 23 Merge k Sorted Lists ---first self conquered Hard, Whooray!

  • 1/19 Fri (5, 145) *****
  1. 11 Container With Most Water
  2. 12 Integer to Roman
  3. 15 3Sum
  4. 16 3Sum Closest

  • 1/18 Thu (3, 140) *****
  1. 5 Longest Palindromic Substring
  2. 6 ZigZag Conversion
  3. 8 String to Integer (atoi)
  4. 10 Regular Expression Matching

  • 1/17 Wed (1, 137) *****
  1. 4 Median of Two Sorted Arrays

  • 1/16 Tue (3, 136) ***** strategy change, focus on the 1-400 for now
  1. 22 Generate Parentheses
  2. 2 Add Two Numbers
  3. 3 Longest Substring Without Repeating Characters

  • 1/15 Mon (1, 133)
  1. 384 Shuffle an Array

  • 1/12 Fri (1, 132)
  1. 421 Maximum XOR of Two Numbers in an Array

  • 1/11 Thu (5, 131)
  1. 503 Next Greater Element II
  2. 454 4Sum II
  3. 648 Replace Words
  4. 646 Maximum Length of Pair Chain
  5. 382 Linked List Random Node

  • 1/10 Wed (3, 126)
  1. 725 Split Linked List in Parts
  2. 94 Binary Tree Inorder Traversal
  3. 477 Total Hamming Distance

  • 1/9 Tue (3, 123)
  1. 547 Friend Circles
  2. 347 Top K Frequent Elements
  3. 672 Bulb Switcher II

  • 1/8 Mon (3, 120)
  1. 529 Minesweeper
  2. 565 Array Nesting
  3. 655 Print Binary Tree

  • 1/7 Sun (3, 117)
  1. 451 Sort Characters By Frequency
  2. 238 Product of Array Except Self
  3. 676 Implement Magic Dictionary

  • 1/4 Thu (1, 114)
  1. 712 Minimum ASCII Delete Sum for Two Strings

  • 1/3 Wed (5, 113)
  1. 609 Find Duplicate File in System
  2. 677 Map Sum Pairs
  3. 462 Minimum Moves to Equal Array Elements II
  4. 495 Teemo Attacking
  5. 667 Beautiful Arrangement II

  • 1/2 Tue (3, 108)
  1. 526 Beautiful Arrangement
  2. 739 Daily Temperatures
  3. 260 Single Number III

  • 1/1 Mon Happy New Year (5, 105)
  1. 540 Single Element in a Sorted Array
  2. 647 Palindrome Substrings
  3. 515 Find Largest Value in Each Tree Row
  4. 748 Shortest Completing Word
  5. 413 Arithmetic Slices
  6. 526 Beautiful Arrangement

  • 12/31 Sun (5, 100)
  1. 537 Complex Number Multiplication
  2. 419 Battleships in a Board
  3. 338 Counting Bits
  4. 442 Find All Duplicates in an Array
  5. 406 Queue Reconstruction by Height

  • 12/30 Sat (3, 95)
  1. 665 Non-decreasing Array
  2. 535 Encode and Decode TinyURL
  3. 654 Maximum Binary Tree

  • 12/29 Fri (5, 92)
  1. 204 Count Primes
  2. 278 First Bad Version
  3. 189 Rotate Array
  4. 479 Largest Palindrome Product
  5. 7 Reverse Integer

  • 12/28 Thu (10, 87)
  1. 155 Min Stack
  2. 475 Heaters
  3. 190 Reverse Bits
  4. 581 Shortest Unsorted Continuous Subarray
  5. 28 Implement strStr()
  6. 69 Sqrt(x)
  7. 532 K-diff Pairs in an Array
  8. 414 Third Maximum Number
  9. 168 Excel Sheet Column Title
  10. 125 Valid Palindrome

  • 12/27 Wed (6, 77)
  1. 58 Length of Last Word
  2. 14 Longest Common Prefix
  3. 303 Range Sum Query - Immutable
  4. 160 Intersection of Two Linked Lists
  5. 605 Can Place Flowers
  6. 400 Nth Digit

  • 12/26 Tue (5, 71)
  1. 203 Remove Linked list Elements
  2. 219 Contains Duplicate II
  3. 680 Valid Palindrome II
  4. 633 Sum of Square Numbers
  5. 88 Merger Sorted Array

  • 12/25 Mon, Merry Christmas (2, 66)
  1. 290 Word Pattern
  2. 234 Palindrome Linked list

  • 12/24 Sun (4, 64)
  1. 20 Valid Parentheses
  2. 225 Implement Stack using Queues
  3. 67 Add Binary
  4. 507 Perfect Number

  • 12/23 Sat (1, 60)
  1. 438 Find All Anagrams in a String

  • 12/22 Fri (7, 59)
  1. 374 Guess Number Higher or Lower
  2. 38 Guess Number Higher or Lower
  3. 26 Remove Duplicates from Sorted Array
  4. 9 Palindrome Number
  5. 141 Linked List Cycle
  6. 205 Isomorphic Strings
  7. 686 Repeated String Match

  • 12/21 Thu (10, 52)
  1. 53 Maximum Subarray
  2. 645 Set Mismatch
  3. 198 House Robber
  4. 643 Maximum Average Subarray I
  5. 119 Pascal's Triangle II
  6. 232 Implement Queue using Stacks
  7. 443 String Compression
  8. 434 Number of Segments in a String
  9. 172 Fractorial Trailing Zeroes
  10. 1 Two Sum

  • 12/20 Wed (1, 42)
  1. 36 Valid Sudoku
  2. 37 Sudoku Solver -- Not done

  • 12/18 Mon (5, 41)
  1. 628 Maximum Product of Three Numbers
  2. 674 Longest Continuous Increasing Subsequence
  3. 482 License Key Formatting
  4. 724 Find Pivot Index
  5. 720 Longest Word in Dictionary

  • 12/17 Sun (2, 36)
  1. 599 Mininmum Index Sum of Two Lists
  2. 661 Image Smoother

  • 12/16 Sat (1, 34)
  1. 697 Degree of an Array

  • 12/15 Fri (3, 33)
  1. 513 Find Bottom Left Tree Value
  2. 508 Most Frequent Subtree Sum
  3. 116 Populating Next Right Pointers in Each Node

Finished all easy tree problems. Change topic tomorrow.


  • 12/14 Thu (7, 30)
  1. 235 Lowest Common Ancestor of a Binary Search Tree
  2. 563 Binary Tree Tilt
  3. 572 Subtree of Another Tree
  4. 104 Maximum Depth of Binary Tree
  5. 606 Construct String from Binary Tree
  6. 617 Merge Two Binary Trees
  7. 101 Symmetric Tree

  • 12/13 Wed (4, 23)
  1. 543 Diameter of Binary Tree
  2. 112 Path Sum
  3. 111 Minimum Depth of Binary Tree
  4. 110 Balacned Binary Tree

  • 12/12 Tue (2, 19)
  1. 501 Find Mode in Binary Search Tree
  2. 671 Second Minimum Node In a Binary Tree

  • 12/11 Mon (5, 17)
  1. 107 Binary Tree Level Order Traversal II
  2. 226 Invert Binary Tree
  3. 257 Binary Tree Paths
  4. 404 Sum of Left Leaves
  5. 437 Path Sum III

  • 12/10 Sun (3, 12)
  1. 653 Two Sum IV - Input is a BST
  2. 637 Average of Levels in Binary Tree
  3. 100 Same Tree

  • 12/09 Sat (1, 9)
  1. 669 Trim a Binary Search Tree

  • 12/08 Fri (2, 8)
  1. 538 Convert BST to Greater Tree
  2. 687 Longest Univalue Path
  • Made a pathetic solution, big room for improvement

  • 12/07 Thu (5, 6)
  1. 383 Ransom Note
  2. 169 Majority Element
  3. 404 Sum of Left Leaves
  4. 455 Assign Cookies
  5. 687 Longest Univalue Path
  • Unfinished, I need to get more comfortable with trees.

  • 12/06 Wed (1, 1)
  1. 349 Intersection of Two Arrays

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