Skip to main content

Explore Problems

Certifications Quiz Pricing

⌘K

CodePeet 444 Complete DSA Sheet

Course Contents

0/32

Reading & Printing Values Variable Types & Storage Conditional Branching Multi-Way Selection Introduction to Sequential Data(Arrays & Strings)Counted Iteration (for)Conditional Iteration (while)Functions & Parameter Passing Complexity Analysis Primer

Nested Loop Patterns

C++ Standard Library Overview Java Collections Framework

Count Digits of a Number Palindrome Number Greatest Common Divisor of 2 numbers Armstrong Number Finding All Divisors Primality Check

Reverse Integer

Recursion via Repeated Printing Number Series Without Loops print 1 to N using recursion print N to 1 using recursion Sum of First N Natural Numbers Computing Factorial Recursively Reverse an Array using recursion Valid Palindrome Fibonacci Number

Element Frequency Count Sort Array by Increasing Frequency

Introduction to Hashing Frequency of the Most Frequent Element

0/7

Selection Sort Bubble Sort Insertion Sort

Bubble Sort with Recursion Quick Sort

Merge Sort Insertion Sort with Recursion

0/40

Find Maximum in Array Second Maximum Without Sorting Check if Array Is Sorted and Rotated Remove Duplicates from Sorted Array Move Zeroes Binary Search Union of Two Arrays Missing Number Max Consecutive Ones Single Number

Rotate Array Longest Subarray with sum K (Positives)Longest Subarray with sum K (All Integers)

Two Sum Majority Element Best Time to Buy and Sell Stock Row with Most Ones

Sort Colors Maximum Subarray Maximum Sum Subarray with Indices Rearrange Array Elements by Sign Next Permutation Array Leaders Longest Consecutive Sequence Set Matrix Zeroes Rotate Image Spiral Matrix Subarray Sum Equals K

Pascal's Triangle Merge Sorted Array

Majority Element II 3Sum 4Sum Longest Subarray with Zero Sum Merge Intervals Maximum Product Subarray

Count subarrays with given XOR Find Missing and Repeated Values Inversion Count in Array Reverse Pairs

0/30

Binary Search Implement Lower Bound Implement Upper Bound Search Insert Position Floor & Ceiling in Sorted Array Rotation Count in a Rotated Sorted array

Find First and Last Position of Element in Sorted Array Search in Rotated Sorted Array Search in Rotated Sorted Array II Find Minimum in Rotated Sorted Array Single Element in a Sorted Array Find Peak Element

Kth Missing Positive Number

Square Root of an Integer Find nth root of m Koko Eating Bananas Minimum Number of Days to Make m Bouquets Find the Smallest Divisor Given a Threshold Capacity To Ship Packages Within D Days Kth Element of Two Sorted Arrays

Maximize Minimum Distance Minimize Maximum Pages Allocated Split Array Largest Sum Painter's Partition Problem Minimize Max Distance to Gas Station Median of Two Sorted Arrays

Search a 2D Matrix Search a 2D Matrix II Find a Peak Element II

Median in a row-wise sorted Matrix

0/15

Remove Outermost Parentheses Largest Odd Number in String Longest Common Prefix Isomorphic Strings Rotate String Valid Anagram

Reverse Words in a String

Maximum Nesting Depth of the Parentheses Roman to Integer

Sort Characters By Frequency String to Integer (atoi)Substrings with K Distinct Characters Longest Palindromic Substring Sum of Beauty of All Substrings Reverse Words in a String

0/30

Linked List Fundamentals Insertion at a Given Position in a Linked List Length of a linked list Search in Linked List

Delete Node in a Linked List

Doubly Linked List Fundamentals Inserting into a Doubly Linked List Deleting from a Doubly Linked List

Reversing a Doubly Linked List

Middle of the Linked List Reverse Linked List Linked List Cycle Palindrome Linked List Intersection of Two Linked Lists

Linked List Cycle II Cycle Length Detection Odd Even Linked List Remove Nth Node From End of List Delete the Middle Node of a Linked List Sort List Partition a Linked List around a given value Add 1 to a number represented as linked list Add Two Numbers

Find pairs with given sum in doubly linked list

Delete all occurrences of a given key in a doubly linked list Remove duplicates from a sorted doubly linked list

Rotate List Copy List with Random Pointer Flatten a Multilevel Doubly Linked List

Reverse Nodes in k-Group

0/24

Reverse a Stack Recursively

String to Integer (atoi)Pow(x, n)Count Good Numbers Sort a Stack Recursively

Check if there exists a subsequence with sum K

Generate all binary strings Generate Parentheses Subsets Understanding Subsequences Combination Sum Combination Sum II Subset Sums Subsets II Combination Sum III Letter Combinations of a Phone Number

Palindrome Partitioning Word Search Word Break

N-Queens Rat in a Maze M-Coloring Problem Sudoku Solver Expression Add Operators

0/18

Bitwise Operations Overview Check K-th Bit Divisibility by 3 Check Power of Two Counting Set Bits Toggle Rightmost Unset Bit XOR-Based Number swap

Divide Two Integers

Minimum Bit Flips to Convert Number Single Number

Subsets XOR Queries of a Subarray Two odd Occuring Numbers in an Array

All divisors of a Number

Count Primes Pow(x, n)

Prime Factorization Sieve-Based Prime Factorization

0/30

Implement stack using array Queue using Array Implement Stack using Queues Implement Queue using Stacks Stack using Linked List Queue using Linked List Valid Parentheses

Infix to Postfix Using Stack Prefix to Infix Conversion Prefix to Postfix Conversion Postfix to Prefix Conversion Postfix to Infix Conversion Infix to Prefix Conversion

Next Greater Element I Previous Smaller Element Count of Greater Elements to Right

Next Greater Element II Sum of Subarray Minimums Asteroid Collision Sum of Subarray Ranges Remove K Digits

Trapping Rain Water Largest Rectangle in Histogram Maximal Rectangle

Online Stock Span LRU Cache

Sliding Window Maximum The Celebrity Problem LFU Cache

0/13

Longest Substring Without Repeating Characters Max Consecutive Ones III Fruit Into Baskets Longest Repeating Character Replacement Binary Subarrays With Sum Count Number of Nice Subarrays Number of Substrings Containing All Three Characters Maximum Points You Can Obtain from Cards Number of Subsequences That Satisfy the Given Sum Condition

Longest Substring with At Most K Distinct Characters

Subarrays with K Different Integers Minimum Window Substring Minimum Window Subsequence

0/17

Priority Queue via Binary Heap Min-Heap & Max-Heap Implementation Validate Heap Property in Array Convert Min Heap to Max Heap

Sort Nearly Sorted Array Rank Transform of an Array

Kth Largest Element in an Array Kth Smallest Element Task Scheduler Hand of Straights

Merge k Sorted Lists

Kth Largest Element in a Stream

Design Twitter Minimum Cost Rope Connection Top K Frequent Elements

Maximum Sum Combination Find Median from Data Stream

0/16

Assign Cookies Lemonade Change Minimum Number of Coins

Fractional Knapsack Valid Parenthesis String

Activity Selection Jump Game Jump Game II Minimum Railway Platforms Job Sequencing Problem Shortest Job First Scheduling LRU Page Replacement Insert Interval Merge Intervals Non-overlapping Intervals

0/34

Tree Data Structure Basics Binary Tree Representation Binary Tree Representation (Java)Binary Tree Traversals Binary Tree Preorder Traversal Binary Tree Inorder Traversal Binary Tree Postorder Traversal All Three Traversals

Binary Tree Level Order Traversal

Maximum Depth of Binary Tree Balanced Binary Tree Diameter of Binary Tree Same Tree Symmetric Tree

Binary Tree Zigzag Level Order Traversal Boundary of Binary Tree Top View of a Binary Tree Bottom View of Binary Tree Binary Tree Right Side View

Binary Tree Maximum Path Sum Vertical Order Traversal of a Binary Tree

Count Complete Tree Nodes Binary Tree Inorder Traversal Binary Tree Paths

Lowest Common Ancestor of a Binary Tree Maximum Width of Binary Tree All Nodes Distance K in Binary Tree Conditions for Unique Tree Construction Construct Binary Tree from Preorder and Inorder Traversal Construct Binary Tree from Inorder and Postorder Traversal Flatten Binary Tree to Linked List

Children Sum in a Binary Tree Time to Burn Entire Tree from a Node Serialize and Deserialize Binary Tree

0/16

BST Fundamentals & Properties Search in a Binary Search Tree

Minimum & Maximum in a BST

Ceil in BST Floor in BST Two Sum IV - Input is a BST

Insert into a Binary Search Tree Delete Node in a BST Kth Smallest Element in a BST Validate Binary Search Tree Lowest Common Ancestor of a Binary Search Tree Construct Binary Search Tree from Preorder Traversal Inorder Successor in BST Binary Search Tree Iterator Recover Binary Search Tree

Largest BST Subtree

0/52

Graph Types & Terminology Graph Representation (C++)Graph Representation (Java)

Number of Connected Components in an Undirected Graph Breadth-First Search Depth-First Search

Number of Provinces Connected Components in Grid Rotting Oranges 01 Matrix Surrounded Regions Number of Enclaves Is Graph Bipartite?Course Schedule II

Detect Cycle in Undirected Graph Word Ladder Word Ladder II Number of Distinct Islands II

Course Schedule Course Schedule II Find Eventual Safe States

Topological Sort Kahn's Algorithm (BFS Topo Sort)Detect Cycle in Directed Graph Alien Dictionary

Shortest Path in Binary Matrix Path With Minimum Effort Cheapest Flights Within K Stops Network Delay Time Number of Ways to Arrive at Destination Find the City With the Smallest Number of Neighbors at a Threshold Distance

Shortest Path in Unweighted Graph Shortest Path in DAG Dijkstra's Algorithm Dijkstra: Queue vs Priority Queue Minimum Steps via Multiply & Mod Bellman-Ford Algorithm Floyd-Warshall Algorithm

Number of Operations to Make Network Connected Most Stones Removed with Same Row or Column Accounts Merge

Minimum Spanning Tree Concepts Prim's Algorithm Disjoint Set (Union-Find)Kruskal's Algorithm Number of Islands II Making a Large Island Swim in Rising Water

Critical Connections in a Network Articulation Points (Cut Vertices)Kosaraju's Algorithm (Strongly Connected Components)

0/56

Introduction to Dynamic Programming

Climbing Stairs

Frog Jump with Variable Steps House Robber House Robber II

Maximum Profit in Job Scheduling Frog Jump

Ninja's Training Unique Paths Unique Paths II Minimum Path Sum Triangle Minimum Falling Path Sum Ninja and his friends

Partition Equal Subset Sum Coin Change Target Sum

Subset Sum Equal to Target Partition Array Into Two Arrays to Minimize Sum Difference Count Subset With Target Sum Count Partitions with Target Difference Coin Change 2 Unbounded Knapsack Problem(Repetition of items allowed)Rod Cutting

Longest Common Subsequence Longest Palindromic Subsequence Delete Operation for Two Strings Edit Distance Print Longest Common Subsequence

Longest Common Substring Minimum Insertion Steps to Make a String Palindrome Shortest Common Supersequence Distinct Subsequences Wildcard Matching

Best Time to Buy and Sell Stock

Best Time to Buy and Sell Stock II Best Time to Buy and Sell Stock with Cooldown Best Time to Buy and Sell Stock with Transaction Fee

Best Time to Buy and Sell Stock III Best Time to Buy and Sell Stock IV

Longest Increasing Subsequence Print the Longest Increasing Subsequence Largest Divisible Subset Longest String Chain Longest Bitonic Subsequence Number of Longest Increasing Subsequence

Partition Array for Maximum Sum

Matrix Chain Multiplication Matrix Chain Multiplication Bottom-Up Approach Minimum Cost to Cut a Stick Burst Balloons Evaluate Boolean Expression Palindrome Partitioning II

Count Square Submatrices with All Ones

Maximal Rectangle

0/7

Implement Trie (Prefix Tree)

Complete String (All Prefixes Exist)Count Distinct Substrings via Trie Maximum XOR of Two Numbers in an Array

Enhanced Trie with Count Bitwise Foundations for Tries Maximum XOR With an Element From Array

0/8

Minimum Add to Make Parentheses Valid Count and Say Polynomial Rolling Hash Repeated String Match

KMP / Rabin-Karp String Search Shortest Palindrome Longest Happy Prefix Count Palindromic Subsequences

Best Time to Buy and Sell Stock IV

Find the maximum profit from daily stock prices when you may complete at most k buy-and-sell transactions and hold only one share at a time — return 0 if none is profitable.

Loading...

Loading content...