Grid 169 Questions

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Week 1

2 / 58

1

Two Sum

Easy·15 mins

2

Valid Parentheses

Easy·20 mins

3

Merge Two Sorted Lists

Easy·20 mins

4

Best Time to Buy and Sell Stock

Easy·20 mins

5

Valid Palindrome

Easy·15 mins

6

Invert Binary Tree

Easy·15 mins

7

Valid Anagram

Easy·15 mins

8

Binary Search

Easy·15 mins

9

Flood Fill

Easy·20 mins

10

Lowest Common Ancestor of a Binary Search Tree

Easy·20 mins

11

Balanced Binary Tree

Easy·15 mins

12

Linked List Cycle

Easy·20 mins

13

Implement Queue using Stacks

Easy·20 mins

14

First Bad Version

Easy·20 mins

15

Ransom Note

Easy·15 mins

16

Climbing Stairs

Easy·20 mins

17

Longest Palindrome

Easy·20 mins

18

Reverse Linked List

Easy·20 mins

19

Majority Element

Easy·20 mins

20

Add Binary

Easy·15 mins

21

Diameter of Binary Tree

Easy·30 mins

22

Middle of the Linked List

Easy·20 mins

23

Maximum Depth of Binary Tree

Easy·15 mins

24

Contains Duplicate

Easy·15 mins

25

Meeting Rooms

Easy·20 mins

26

Roman to Integer

Easy·20 mins

27

Backspace String Compare

Easy·15 mins

28

Counting Bits

Easy·15 mins

29

Same Tree

Easy·20 mins

30

Number of 1 Bits

Easy·15 mins

31

Longest Common Prefix

Easy·20 mins

32

Single Number

Easy·15 mins

33

Palindrome Linked List

Easy·20 mins

34

Move Zeroes

Easy·20 mins

35

Symmetric Tree

Easy·20 mins

36

Missing Number

Easy·15 mins

37

Palindrome Number

Easy·15 mins

38

Convert Sorted Array to Binary Search Tree

Easy·20 mins

39

Reverse Bits

Easy·15 mins

40

Subtree of Another Tree

Easy·20 mins

41

Squares of a Sorted Array

Easy·20 mins

42

Maximum Subarray

Medium·20 mins

43

Insert Interval

Medium·25 mins

44

01 Matrix

Medium·30 mins

45

K Closest Points to Origin

Medium·30 mins

46

Longest Substring Without Repeating Characters

Medium·30 mins

47

3Sum

Medium·30 mins

48

Binary Tree Level Order Traversal

Medium·20 mins

49

Clone Graph

Medium·25 mins

50

Evaluate Reverse Polish Notation

Medium·30 mins

51

Course Schedule

Medium·30 mins

52

Implement Trie (Prefix Tree)

Medium·35 mins

53

Coin Change

Medium·25 mins

54

Product of Array Except Self

Medium·30 mins

55

Min Stack

Medium·20 mins

56

Validate Binary Search Tree

Medium·20 mins

57

Number of Islands

Medium·25 mins

58

Rotting Oranges

Medium·30 mins

Week 2

0 / 42

1

Search in Rotated Sorted Array

Medium·30 mins

2

Combination Sum

Medium·30 mins

3

Permutations

Medium·30 mins

4

Merge Intervals

Medium·30 mins

5

Lowest Common Ancestor of a Binary Tree

Medium·25 mins

6

Time Based Key-Value Store

Medium·35 mins

7

Accounts Merge

Medium·30 mins

8

Sort Colors

Medium·25 mins

9

Word Break

Medium·30 mins

10

Partition Equal Subset Sum

Medium·30 mins

11

String to Integer (atoi)

Medium·25 mins

12

Spiral Matrix

Medium·25 mins

13

Subsets

Medium·30 mins

14

Binary Tree Right Side View

Medium·20 mins

15

Longest Palindromic Substring

Medium·25 mins

16

Unique Paths

Medium·20 mins

17

Construct Binary Tree from Preorder and Inorder Traversal

Medium·25 mins

18

Container With Most Water

Medium·35 mins

19

Letter Combinations of a Phone Number

Medium·30 mins

20

Word Search

Medium·30 mins

21

Find All Anagrams in a String

Medium·30 mins

22

Minimum Height Trees

Medium·30 mins

23

Task Scheduler

Medium·35 mins

24

LRU Cache

Medium·30 mins

25

Kth Smallest Element in a BST

Medium·25 mins

26

Daily Temperatures

Medium·30 mins

27

House Robber

Medium·25 mins

28

Gas Station

Medium·30 mins

29

Next Permutation

Medium·30 mins

30

Valid Sudoku

Medium·35 mins

31

Group Anagrams

Medium·25 mins

32

Maximum Product Subarray

Medium·30 mins

33

Design Add and Search Words Data Structure

Medium·35 mins

34

Pacific Atlantic Water Flow

Medium·30 mins

35

Remove Nth Node From End of List

Medium·20 mins

36

Shortest Path to Get Food

Medium·30 mins

37

Find the Duplicate Number

Medium·20 mins

38

Top K Frequent Words

Medium·30 mins

39

Longest Increasing Subsequence

Medium·30 mins

40

Graph Valid Tree

Medium·30 mins

41

Course Schedule II

Medium·35 mins

42

Swap Nodes in Pairs

Medium·25 mins

Week 3

0 / 44

1

Path Sum II

Medium·25 mins

2

Longest Consecutive Sequence

Medium·30 mins

3

Rotate Array

Medium·25 mins

4

Odd Even Linked List

Medium·25 mins

5

Decode String

Medium·30 mins

6

Contiguous Array

Medium·30 mins

7

Maximum Width of Binary Tree

Medium·20 mins

8

Find K Closest Elements

Medium·30 mins

9

Longest Repeating Character Replacement

Medium·30 mins

10

Inorder Successor in BST

Medium·30 mins

11

Jump Game

Medium·20 mins

12

Add Two Numbers

Medium·25 mins

13

Generate Parentheses

Medium·25 mins

14

Sort List

Medium·25 mins

15

Number of Connected Components in an Undirected Graph

Medium·30 mins

16

Minimum Knight Moves

Medium·35 mins

17

Subarray Sum Equals K

Medium·35 mins

18

Asteroid Collision

Medium·30 mins

19

Random Pick with Weight

Medium·25 mins

20

Kth Largest Element in an Array

Medium·30 mins

21

Maximal Square

Medium·30 mins

22

Rotate Image

Medium·25 mins

23

Binary Tree Zigzag Level Order Traversal

Medium·25 mins

24

Design Hit Counter

Medium·30 mins

25

Path Sum III

Medium·35 mins

26

Pow(x, n)

Medium·20 mins

27

Search a 2D Matrix

Medium·30 mins

28

Largest Number

Medium·20 mins

29

Decode Ways

Medium·25 mins

30

Meeting Rooms II

Medium·30 mins

31

Reverse Integer

Medium·25 mins

32

Set Matrix Zeroes

Medium·25 mins

33

Reorder List

Medium·25 mins

34

Encode and Decode Strings

Medium·25 mins

35

Cheapest Flights Within K Stops

Medium·45 mins

36

All Nodes Distance K in Binary Tree

Medium·25 mins

37

3Sum Closest

Medium·30 mins

38

Rotate List

Medium·25 mins

39

Find Minimum in Rotated Sorted Array

Medium·30 mins

40

Basic Calculator II

Medium·30 mins

41

Combination Sum IV

Medium·35 mins

42

Insert Delete GetRandom O(1)

Medium·20 mins

43

Non-overlapping Intervals

Medium·20 mins

44

Minimum Window Substring

Hard·30 mins

Week 4

0 / 25

1

Serialize and Deserialize Binary Tree

Hard·40 mins

2

Trapping Rain Water

Hard·35 mins

3

Find Median from Data Stream

Hard·30 mins

4

Word Ladder

Hard·45 mins

5

Basic Calculator

Hard·40 mins

6

Maximum Profit in Job Scheduling

Hard·45 mins

7

Merge k Sorted Lists

Hard·30 mins

8

Largest Rectangle in Histogram

Hard·35 mins

9

Binary Tree Maximum Path Sum

Hard·35 mins

10

Maximum Frequency Stack

Hard·40 mins

11

Median of Two Sorted Arrays

Hard·40 mins

12

Longest Increasing Path in a Matrix

Hard·40 mins

13

Longest Valid Parentheses

Hard·35 mins

14

Design In-Memory File System

Hard·40 mins

15

Employee Free Time

Hard·35 mins

16

Word Search II

Hard·40 mins

17

Alien Dictionary

Hard·45 mins

18

Bus Routes

Hard·45 mins

19

Sliding Window Maximum

Hard·35 mins

20

Palindrome Pairs

Hard·40 mins

21

Reverse Nodes in k-Group

Hard·35 mins

22

Sudoku Solver

Hard·40 mins

23

First Missing Positive

Hard·35 mins

24

N-Queens

Hard·40 mins

25

Smallest Range Covering Elements from K Lists

Hard·40 mins