All DSA Sheets

    CS 45 Sheet

    Customize study plans according to your needs. You are recommended to work on the questions in order.

    Questions Summary

    We have selected these 45 problems. It should take around 18 hours for an average person to solve these problems.

    difficulty

    Questions grouped by difficulty

    Easy: 20
    Medium: 21
    Hard: 4

    topics

    Questions grouped by topics

    Array: 6
    Stack: 3
    Linked List: 5
    Binary Search: 4
    Graph: 5
    Binary Tree: 2
    Hash Table: 1
    String: 8
    Binary: 2
    Math: 2
    Trie: 1
    Dynamic Programming: 3
    Matrix: 1
    Heap: 2

    Completed 0 / 45

    You can now bookmark the page to save your preferences! We also recently changed the questions presentation settings.

    1
    Two Sum
    easy
    ·
    15 mins
    ·
    Array
    2
    Valid Parentheses
    easy
    ·
    20 mins
    ·
    Stack
    3
    Merge Two Sorted Lists
    easy
    ·
    20 mins
    ·
    Linked List
    4
    Binary Search
    easy
    ·
    15 mins
    ·
    Binary Search
    5
    Flood Fill
    easy
    ·
    20 mins
    ·
    Graph
    6
    Balanced Binary Tree
    easy
    ·
    15 mins
    ·
    Binary Tree
    7
    Linked List Cycle
    easy
    ·
    20 mins
    ·
    Linked List
    8
    Implement Queue using Stacks
    easy
    ·
    20 mins
    ·
    Stack
    9
    First Bad Version
    easy
    ·
    20 mins
    ·
    Binary Search
    10
    Ransom Note
    easy
    ·
    15 mins
    ·
    Hash Table
    11
    Longest Palindrome
    easy
    ·
    20 mins
    ·
    String
    12
    Majority Element
    easy
    ·
    20 mins
    ·
    Array
    13
    Add Binary
    easy
    ·
    15 mins
    ·
    Binary
    14
    Middle of the Linked List
    easy
    ·
    20 mins
    ·
    Linked List
    15
    Roman to Integer
    easy
    ·
    20 mins
    ·
    Math
    16
    Backspace String Compare
    easy
    ·
    15 mins
    ·
    Stack
    17
    Longest Common Prefix
    easy
    ·
    20 mins
    ·
    String
    18
    Missing Number
    easy
    ·
    15 mins
    ·
    Binary
    19
    Palindrome Number
    easy
    ·
    15 mins
    ·
    Math
    20
    Longest Substring Without Repeating Characters
    medium
    ·
    30 mins
    ·
    String
    21
    3Sum
    medium
    ·
    30 mins
    ·
    Array
    22
    Clone Graph
    medium
    ·
    25 mins
    ·
    Graph
    23
    Search in Rotated Sorted Array
    medium
    ·
    30 mins
    ·
    Binary Search
    24
    Combination Sum
    medium
    ·
    30 mins
    ·
    Array
    25
    Word Break
    medium
    ·
    30 mins
    ·
    Trie
    26
    Longest Palindromic Substring
    medium
    ·
    25 mins
    ·
    String
    27
    Container With Most Water
    medium
    ·
    35 mins
    ·
    Array
    28
    Group Anagrams
    medium
    ·
    25 mins
    ·
    String
    29
    Maximum Product Subarray
    medium
    ·
    30 mins
    ·
    Dynamic Programming
    30
    Pacific Atlantic Water Flow
    medium
    ·
    30 mins
    ·
    Graph
    31
    Remove Nth Node From End of List
    medium
    ·
    20 mins
    ·
    Linked List
    32
    Longest Increasing Subsequence
    medium
    ·
    30 mins
    ·
    Dynamic Programming
    33
    Graph Valid Tree
    medium
    ·
    30 mins
    ·
    Graph
    34
    Longest Consecutive Sequence
    medium
    ·
    30 mins
    ·
    Array
    35
    Longest Repeating Character Replacement
    medium
    ·
    30 mins
    ·
    String
    36
    Rotate Image
    medium
    ·
    25 mins
    ·
    Matrix
    37
    Reorder List
    medium
    ·
    25 mins
    ·
    Linked List
    38
    Encode and Decode Strings
    medium
    ·
    25 mins
    ·
    String
    39
    Find Minimum in Rotated Sorted Array
    medium
    ·
    30 mins
    ·
    Binary Search
    40
    Serialize and Deserialize Binary Tree
    hard
    ·
    40 mins
    ·
    Binary Tree
    41
    Find Median from Data Stream
    hard
    ·
    30 mins
    ·
    Heap
    42
    Merge k Sorted Lists
    hard
    ·
    30 mins
    ·
    Heap
    43
    Alien Dictionary
    hard
    ·
    45 mins
    ·
    Graph
    44
    Assign Cookies
    easy
    ·
    15 mins
    ·
    Dynamic Programming
    45
    Palindromic Substrings
    medium
    ·
    20 mins
    ·
    String

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    Questions Summary

    We have selected these 45 problems. It should take around 18 hours for an average person to solve these problems.

    difficulty

    Questions grouped by difficulty

    Easy: 20
    Medium: 21
    Hard: 4

    topics

    Questions grouped by topics

    Array: 6
    Stack: 3
    Linked List: 5
    Binary Search: 4
    Graph: 5
    Binary Tree: 2
    Hash Table: 1
    String: 8
    Binary: 2
    Math: 2
    Trie: 1
    Dynamic Programming: 3
    Matrix: 1
    Heap: 2