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Study plan
Study Plan
Complete and win badges
Array948
String470
Dynamic Programming335
Hash Table335
Math322
Depth-First Search231
Sorting208
Greedy203
Breadth-First Search185
Tree182
Database180
Binary Search154
Binary Tree153
Matrix145
Two Pointers135
Bit Manipulation119
Stack113
Design99
Heap (Priority Queue)95
Backtracking83
Graph76
Simulation68
Prefix Sum63
Sliding Window61
Linked List58
Union Find56
Counting55
Recursion42
Binary Search Tree40
Trie39
Monotonic Stack37
Divide and Conquer36
Ordered Set33
Bitmask30
Queue29
Geometry26
Memoization26
Game Theory22
Enumeration20
Hash Function20
Segment Tree19
Topological Sort19
Interactive18
String Matching15
Binary Indexed Tree15
Data Stream14
Rolling Hash13
Randomized12
Shortest Path11
Combinatorics10
Iterator9
Concurrency9
Monotonic Queue8
Number Theory8
Brainteaser8
Probability and Statistics7
Doubly-Linked List7
Merge Sort7
Quickselect6
Bucket Sort6
Minimum Spanning Tree5
Counting Sort5
Suffix Array5
Shell4
Line Sweep4
Reservoir Sampling4
Strongly Connected Component2
Eulerian Circuit2
Radix Sort2
Rejection Sampling2
Biconnected Component1
Expand
All Topics
Algorithms
Database
Shell
Concurrency
Status
Title
Company
Solution
Acceptance
Difficulty
Frequency
1. Two Sum
47.6%
Easy
2. Add Two Numbers
36.9%
Medium
3. Longest Substring Without Repeating Characters
32.2%
Medium
4. Median of Two Sorted Arrays
32.7%
Hard
5. Longest Palindromic Substring
31.2%
Medium
6. ZigZag Conversion
39.7%
Medium
7. Reverse Integer
26.1%
Easy
8. String to Integer (atoi)
16.0%
Medium
9. Palindrome Number
51.4%
Easy
10. Regular Expression Matching
27.9%
Hard
11. Container With Most Water
53.1%
Medium
12. Integer to Roman
58.2%
Medium
13. Roman to Integer
57.6%
Easy
14. Longest Common Prefix
37.8%
Easy
15. 3Sum
29.4%
Medium
16. 3Sum Closest
46.8%
Medium
17. Letter Combinations of a Phone Number
51.6%
Medium
18. 4Sum
36.6%
Medium
19. Remove Nth Node From End of List
36.9%
Medium
20. Valid Parentheses
40.4%
Easy
21. Merge Two Sorted Lists
57.9%
Easy
22. Generate Parentheses
68.0%
Medium
23. Merge k Sorted Lists
44.6%
Hard
24. Swap Nodes in Pairs
55.5%
Medium
25. Reverse Nodes in k-Group
48.3%
Hard
26. Remove Duplicates from Sorted Array
47.6%
Easy
27. Remove Element
50.3%
Easy
28. Implement strStr()
35.7%
Easy
29. Divide Two Integers
17.0%
Medium
30. Substring with Concatenation of All Words
27.1%
Hard
31. Next Permutation
34.6%
Medium
32. Longest Valid Parentheses
30.6%
Hard
33. Search in Rotated Sorted Array
36.8%
Medium
34. Find First and Last Position of Element in Sorted Array
38.7%
Medium
35. Search Insert Position
42.6%
Easy
36. Valid Sudoku
53.0%
Medium
37. Sudoku Solver
50.9%
Hard
38. Count and Say
47.4%
Medium
39. Combination Sum
62.0%
Medium
40. Combination Sum II
51.4%
Medium
41. First Missing Positive
35.0%
Hard
42. Trapping Rain Water
53.7%
Hard
43. Multiply Strings
36.0%
Medium
44. Wildcard Matching
26.0%
Hard
45. Jump Game II
34.5%
Medium
46. Permutations
69.4%
Medium
47. Permutations II
51.7%
Medium
48. Rotate Image
63.5%
Medium
49. Group Anagrams
61.9%
Medium
50. Pow(x, n)
31.5%
Medium
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