Airbnb Amazon Anagrams Array BFS Binary Binary Search Binary Search Tree Binary Tree Binary Tree Traversal Bit Manipulation Bloomberg Breadth First Search Consecutive Subsequences Cracking The Coding Interview Depth First Search Depth-first Search Dynamic Programming Enumeration Facebook Forward-Backward Traversal Game Game Theory Google Greedy Hash Table Heap High Precision Integer Linked List LinkedIn Math Mathematics Microsoft Paid Queue Sort Sorted Array String Subarray Subsquences Tree Twitter Two Pointers Uber Union Find Zenefits binary tree string

## Airbnb

# | Title | Difficulty |
---|---|---|

1 | Big Integer Addition | Easy |

## Amazon

# | Title | Difficulty |
---|---|---|

1 | Convert BST to Greater Tree | Easy |

2 | First Position Unique Character | Easy |

3 | K Closest Points | Medium |

4 | Longest Palindrome | Easy |

5 | Substring Anagrams | Easy |

## Anagrams

# | Title | Difficulty |
---|---|---|

1 | Anagrams | Medium |

2 | Substring Anagrams | Easy |

## Array

# | Title | Difficulty |
---|---|---|

1 | Coins in a Line II | Medium |

2 | Coins in a Line III | Hard |

3 | Coins in a Line | Easy |

4 | Continuous Subarray Sum | Medium |

5 | Find K Closest Elements | Medium |

6 | Longest Increasing Continuous Subsequence | Easy |

7 | Maximum Average Subarray I | Easy |

8 | Maximum Product of Three Numbers | Easy |

9 | Maximum Subarray II | Medium |

10 | Maximum Subarray | Easy |

11 | Merge Sorted Array | Easy |

12 | Move Zeroes | Easy |

13 | Partition Array | Medium |

14 | Pascal's Triangle II | Easy |

15 | Plus One | Easy |

16 | Search for a Range | Medium |

17 | Split Array into Consecutive Subsequences | Medium |

18 | Two Sum | Easy |

## BFS

# | Title | Difficulty |
---|---|---|

1 | Maximum Width of Binary Tree | Medium |

## Binary

# | Title | Difficulty |
---|---|---|

1 | Count 1 in Binary | Easy |

## Binary Search

# | Title | Difficulty |
---|---|---|

1 | Classical Binary Search | Easy |

2 | Guess Number Game | Easy |

3 | Intersection of Two Arrays II | Easy |

4 | Intersection of Two Arrays | Easy |

5 | Longest Increasing Subsequence | Medium |

6 | Search for a Range | Medium |

## Binary Search Tree

# | Title | Difficulty |
---|---|---|

1 | Convert BST to Greater Tree | Easy |

## Binary Tree

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Level Order Traversal | Easy |

2 | Binary Tree Path Sum | Easy |

3 | Binary Tree Paths | Easy |

4 | Convert BST to Greater Tree | Easy |

5 | Flatten Binary Tree to Linked List | Easy |

6 | Identical Binary Tree | Easy |

7 | Invert Binary Tree | Easy |

8 | Lowest Common Ancestor | Medium |

9 | Minimum Depth of Binary Tree | Easy |

## Binary Tree Traversal

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Level Order Traversal | Easy |

2 | Binary Tree Path Sum | Easy |

3 | Binary Tree Paths | Easy |

## Bit Manipulation

# | Title | Difficulty |
---|---|---|

1 | Count 1 in Binary | Easy |

2 | O(1) Check Power of 2 | Easy |

3 | Swap Bits | Easy |

## Bloomberg

# | Title | Difficulty |
---|---|---|

1 | First Position Unique Character | Easy |

## Breadth First Search

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Level Order Traversal | Easy |

## Consecutive Subsequences

# | Title | Difficulty |
---|---|---|

1 | Split Array into Consecutive Subsequences | Medium |

## Cracking The Coding Interview

# | Title | Difficulty |
---|---|---|

1 | Add Two Numbers | Easy |

2 | Climbing Stairs II | Easy |

## Depth First Search

# | Title | Difficulty |
---|---|---|

1 | Flatten Binary Tree to Linked List | Easy |

2 | Minimum Depth of Binary Tree | Easy |

## Depth-first Search

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Path Sum | Easy |

2 | Binary Tree Paths | Easy |

## Dynamic Programming

# | Title | Difficulty |
---|---|---|

1 | Climbing Stairs | Easy |

2 | Coins in a Line II | Medium |

3 | Coins in a Line III | Hard |

4 | Coins in a Line | Easy |

5 | Decode Ways | Medium |

6 | Longest Increasing Continuous Subsequence | Easy |

7 | Longest Increasing Subsequence | Medium |

8 | Paint Fence | Easy |

## Enumeration

# | Title | Difficulty |
---|---|---|

1 | Longest Increasing Continuous Subsequence | Easy |

2 | Maximum Subarray II | Medium |

3 | Maximum Subarray | Easy |

# | Title | Difficulty |
---|---|---|

1 | Anagrams | Medium |

2 | Big Integer multiplication | Medium |

3 | Binary Tree Level Order Traversal | Easy |

4 | Binary Tree Paths | Easy |

5 | Count and Say | Easy |

6 | Lowest Common Ancestor | Medium |

7 | Reverse Linked List | Easy |

## Forward-Backward Traversal

# | Title | Difficulty |
---|---|---|

1 | Maximum Subarray II | Medium |

## Game

# | Title | Difficulty |
---|---|---|

1 | Judge Route Circle | Easy |

## Game Theory

# | Title | Difficulty |
---|---|---|

1 | Coins in a Line II | Medium |

2 | Coins in a Line III | Hard |

3 | Coins in a Line | Easy |

# | Title | Difficulty |
---|---|---|

1 | Big Integer Addition | Easy |

2 | Binary Tree Paths | Easy |

3 | Guess Number Game | Easy |

4 | LRU Cache | Hard |

## Greedy

# | Title | Difficulty |
---|---|---|

1 | Coins in a Line | Easy |

2 | Maximum Subarray II | Medium |

3 | Maximum Subarray | Easy |

## Hash Table

# | Title | Difficulty |
---|---|---|

1 | Anagrams | Medium |

2 | Happy Number | Easy |

3 | Intersection of Two Arrays II | Easy |

4 | Intersection of Two Arrays | Easy |

5 | Longest Palindrome | Easy |

6 | Longest Substring with At Most K Distinct Characters | Medium |

7 | Substring Anagrams | Easy |

## Heap

# | Title | Difficulty |
---|---|---|

1 | K Closest Points | Medium |

## High Precision

# | Title | Difficulty |
---|---|---|

1 | Add Two Numbers II | Medium |

2 | Add Two Numbers | Easy |

## Integer

# | Title | Difficulty |
---|---|---|

1 | Palindrome Number | Easy |

## Linked List

# | Title | Difficulty |
---|---|---|

1 | Add Two Numbers II | Medium |

2 | Add Two Numbers | Easy |

3 | LRU Cache | Hard |

4 | Merge Two Sorted Lists | Easy |

5 | Reverse Linked List II | Medium |

6 | Reverse Linked List | Easy |

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Level Order Traversal | Easy |

2 | K Closest Points | Medium |

3 | Lowest Common Ancestor | Medium |

4 | Maximum Subarray | Easy |

5 | Merge Two Sorted Lists | Easy |

6 | Valid Number | Hard |

## Math

# | Title | Difficulty |
---|---|---|

1 | Add Digits | Easy |

2 | Add Two Numbers | Easy |

3 | Happy Number | Easy |

## Mathematics

# | Title | Difficulty |
---|---|---|

1 | Add Digits | Easy |

2 | Big Integer Addition | Easy |

3 | Big Integer multiplication | Medium |

4 | Cosine Similarity | Easy |

5 | Happy Number | Easy |

6 | Remove 9 | Hard |

## Microsoft

# | Title | Difficulty |
---|---|---|

1 | First Position Unique Character | Easy |

## Paid

# | Title | Difficulty |
---|---|---|

1 | Longest Substring with At Most K Distinct Characters | Medium |

2 | Paint Fence | Easy |

## Queue

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Level Order Traversal | Easy |

## Sort

# | Title | Difficulty |
---|---|---|

1 | Intersection of Two Arrays II | Easy |

2 | Intersection of Two Arrays | Easy |

3 | Partition Array | Medium |

## Sorted Array

# | Title | Difficulty |
---|---|---|

1 | Merge Sorted Array | Easy |

2 | Search for a Range | Medium |

## String

# | Title | Difficulty |
---|---|---|

1 | Anagrams | Medium |

2 | Big Integer multiplication | Medium |

3 | Count and Say | Easy |

4 | Decode Ways | Medium |

5 | First Position Unique Character | Easy |

6 | Left Pad | Easy |

7 | Length of Last Word | Easy |

8 | Longest Substring with At Most K Distinct Characters | Medium |

9 | Palindrome Number | Easy |

10 | Valid Number | Hard |

## Subarray

# | Title | Difficulty |
---|---|---|

1 | Continuous Subarray Sum | Medium |

2 | Maximum Subarray II | Medium |

3 | Maximum Subarray | Easy |

## Subsquences

# | Title | Difficulty |
---|---|---|

1 | Split Array into Consecutive Subsequences | Medium |

## Tree

# | Title | Difficulty |
---|---|---|

1 | Binary Tree Path Sum | Easy |

2 | Binary Tree Paths | Easy |

3 | Convert BST to Greater Tree | Easy |

4 | Flatten Binary Tree to Linked List | Easy |

5 | Lowest Common Ancestor | Medium |

# | Title | Difficulty |
---|---|---|

1 | Big Integer multiplication | Medium |

## Two Pointers

# | Title | Difficulty |
---|---|---|

1 | Intersection of Two Arrays II | Easy |

2 | Intersection of Two Arrays | Easy |

3 | Longest Substring with At Most K Distinct Characters | Medium |

4 | Move Zeroes | Easy |

5 | Partition Array | Medium |

## Uber

# | Title | Difficulty |
---|---|---|

1 | Anagrams | Medium |

2 | Binary Tree Level Order Traversal | Easy |

3 | LRU Cache | Hard |

4 | Reverse Linked List | Easy |

## Union Find

# | Title | Difficulty |
---|---|---|

1 | Connecting Graph | Medium |

## Zenefits

# | Title | Difficulty |
---|---|---|

1 | LRU Cache | Hard |

## binary tree

# | Title | Difficulty |
---|---|---|

1 | Maximum Width of Binary Tree | Medium |

## string

# | Title | Difficulty |
---|---|---|

1 | Scramble String | Hard |