daily tracker

Ray (Red) vs Hayden (Green) vs Arthur (Blue)

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Daily Challenge - Day 73 (Started Dec 8, 2025)

🟢 Easy	🟡 Medium	🔴 Hard	📐 Project Euler (2/day)	🚀 NeetCode
Check if Matrix Is X-Matrix	Wiggle Sort II	Minimum Number of Refueling Stops	Problem 145 Problem 146	NeetCode Practice

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total growth over time

note: a 0.1 jitter is added to scores so lines don't overlap if we are tied

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📊 Category Breakdown

LeetCode	NeetCode	Project Euler

how to submit

1. go to your folder (eg. ray/leetcode)
2. add your solution file (.py, .js, .cpp etc)
3. Push to main.
4. the bot will update the graphs in ~30 seconds
5. yay!

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Click to view previous challenges

Day	Date	Easy	Medium	Hard	Euler
Day 73	2026-02-18	Check if Matrix Is X-Matrix	Wiggle Sort II	Minimum Number of Refueling Stops	Problem 145 Problem 146
Day 72	2026-02-17	Is Object Empty	Populating Next Right Pointers in Each Node II	Stone Game IV	Torricelli Triangles Laser Beam Reflections
Day 71	2026-02-16	Sum of Elements With Frequency Divisible by K	Shortest and Lexicographically Smallest Beautiful String	Maximum Number of Non-overlapping Palindrome Substrings	Square Progressive Numbers Perfect Square Collection
Day 70	2026-02-15	Count the Digits That Divide a Number	Path In Zigzag Labelled Binary Tree	Maximum Good Subtree Score	Pythagorean Tiles Modified Fibonacci Golden Nuggets
Day 69	2026-02-14	Most Frequent Even Element	Ugly Number III	Minimum Amount of Damage Dealt to Bob	Fibonacci Golden Nuggets Special Isosceles Triangles
Day 68	2026-02-13	Subtract the Product and Sum of Digits of an Integer	Print FooBar Alternately	Candy	Same Differences Singleton Difference
Day 67	2026-02-12	Alternating Groups I	Insufficient Nodes in Root to Leaf Paths	Minimum Cost to Cut a Stick	Repunit Nonfactors Prime Pair Connection
Day 66	2026-02-11	Binary Gap	Airplane Seat Assignment Probability	Find Sum of Array Product of Magical Sequences	Prime Cube Partnership Large Repunit Factors
Day 65	2026-02-10	Matrix Diagonal Sum	Generate Binary Strings Without Adjacent Zeros	Online Majority Element In Subarray	Repunit Divisibility Composites with Prime Repunit Property
Day 64	2026-02-09	Maximum Units on a Truck	Lexicographically Minimum String After Removing Stars	Shortest Path to Get All Keys	abc-hits Hexagonal Tile Differences
Day 63	2026-02-08	Range Sum of BST	Exam Room	Russian Doll Envelopes	Palindromic Sums Cuboid Layers
Day 62	2026-02-07	Valid Perfect Square	Identify the Largest Outlier in an Array	Sum of Scores of Built Strings	Prime Square Remainders Ordered Radicals
Day 61	2026-02-06	Number Complement	Eliminate Maximum Number of Monsters	N-Queens II	Disc Game Prize Fund Efficient Exponentiation
Day 60	2026-02-05	Check if Any Element Has Prime Frequency	Circular Array Loop	Lexicographically Smallest Generated String	Digit Power Sum Square Remainders
Day 59	2026-02-04	Sum of All Subset XOR Totals	Magical String	Check If Digits Are Equal in String After Operations II	Red, Green, and Blue Tiles Pandigital Prime Sets
Day 58	2026-02-03	Count Good Triplets	Count the Hidden Sequences	Redundant Connection II	Counting Block Combinations II Red, Green or Blue Tiles
Day 57	2026-02-02	Find the Longest Balanced Substring of a Binary String	Insert Greatest Common Divisors in Linked List	Maximize the Number of Target Nodes After Connecting Trees II	Non-bouncy Numbers Counting Block Combinations I
Day 56	2026-02-01	Find The Least Frequent Digit	The kth Factor of n	Shortest Path in a Weighted Tree	Primes with Runs Bouncy Numbers
Day 55	2026-01-31	Climbing Stairs	High-Access Employees	Find the Count of Good Integers	Darts Diophantine Reciprocals II
Day 54	2026-01-30	Design an Ordered Stream	Longest Palindromic Subsequence	Minimum Distance to Type a Word Using Two Fingers	Minimal Network Diophantine Reciprocals I
Day 53	2026-01-29	Final Prices With a Special Discount in a Shop	Substring XOR Queries	Maximum Total Beauty of the Gardens	Special Subset Sums: Testing Special Subset Sums: Meta-testing
Day 52	2026-01-28	Degree of an Array	Minimum Number of Food Buckets to Feed the Hamsters	Count Pairs With XOR in a Range	Special Subset Sums: Optimum Pandigital Fibonacci Ends
Day 51	2026-01-27	Absolute Difference Between Maximum and Minimum K Elements	Score of Parentheses	Analyze Organization Hierarchy	Optimum Polynomial Triangle Containment
Day 50	2026-01-26	Find Nearest Point That Has the Same X or Y Coordinate	Find the Longest Substring Containing Vowels in Even Counts	Finding MK Average	Largest Exponential Arranged Probability
Day 49	2026-01-25	Fibonacci Number	Rearrange Array Elements by Sign	Valid Number	Large Non-Mersenne Prime Anagramic Squares
Day 48	2026-01-24	Find Special Substring of Length K	Maximum Product of the Length of Two Palindromic Subsequences	Find Beautiful Indices in the Given Array II	Amicable Chains Su Doku
Day 47	2026-01-23	N-th Tribonacci Number	Subsets	Minimum Operations to Equalize Binary String	Arithmetic Expressions Almost Equilateral Triangles
Day 46	2026-01-22	Sort By	Find the Longest Semi-Repetitive Substring	Check if an Original String Exists Given Two Encoded Strings	Right Triangles with Integer Coordinates Square Digit Chains
Day 45	2026-01-21	Employees Whose Manager Left the Company	Unique Length-3 Palindromic Subsequences	Maximize Cyclic Partition Score	Roman Numerals Cube Digit Pairs
Day 44	2026-01-20	Move Zeroes	Maximum Number of Non-Overlapping Subarrays With Sum Equals Target	Maximum Candies You Can Get from Boxes	Problem 87 Problem 88
Day 43	2026-01-19	Account Balance After Rounded Purchase	Cousins in Binary Tree II	Minimum Possible Integer After at Most K Adjacent Swaps On Digits	Counting Rectangles Cuboid Route
Day 42	2026-01-18	Slowest Key	Remove Nth Node From End of List	Permutation Sequence	Path Sum: Four Ways Monopoly Odds
Day 41	2026-01-17	Binary Search	Minimum Number of Valid Strings to Form Target I	Find the Minimum Area to Cover All Ones II	Path Sum: Two Ways Path Sum: Three Ways
Day 40	2026-01-16	Happy Number	Implement Magic Dictionary	Make Array Empty	Passcode Derivation Square Root Digital Expansion
Day 39	2026-01-15	Remove Outermost Parentheses	Find The First Player to win K Games in a Row	Shortest Subarray with Sum at Least K	Prime Summations Coin Partitions
Day 38	2026-01-14	Check If String Is a Prefix of Array	Most Profitable Path in a Tree	Minimum Cost to Make at Least One Valid Path in a Grid	Singular Integer Right Triangles Counting Summations
Day 37	2026-01-13	Find Mode in Binary Search Tree	Alert Using Same Key-Card Three or More Times in a One Hour Period	Shortest Impossible Sequence of Rolls	Counting Fractions in a Range Digit Factorial Chains
Day 36	2026-01-12	Reverse Only Letters	Minimum Cost to Make Arrays Identical	Total Characters in String After Transformations II	Ordered Fractions Counting Fractions
Day 35	2026-01-11	Find Products with Valid Serial Numbers	Count Zero Request Servers	Basic Calculator IV	Totient Maximum Totient Permutation
Day 34	2026-01-10	Count Negative Numbers in a Sorted Matrix	Stone Game VII	Maximum Profit from Valid Topological Order in DAG	Maximum Path Sum II Magic 5-gon Ring
Day 33	2026-01-09	Sort Array By Parity II	Maximize Score of Numbers in Ranges	Dice Roll Simulation	Convergents of $e$ Diophantine Equation
Day 32	2026-01-08	Find Target Indices After Sorting Array	Minimum Number of Coins to be Added	Maximize the Distance Between Points on a Square	Powerful Digit Counts Odd Period Square Roots
Day 31	2026-01-07	Largest Even Number	Beautiful Towers II	Maximum Number of K-Divisible Components	Cyclical Figurate Numbers Cubic Permutations
Day 30	2026-01-06	Count Prefix and Suffix Pairs I	Taking Maximum Energy From the Mystic Dungeon	Number of Increasing Paths in a Grid	XOR Decryption Prime Pair Sets
Day 29	2026-01-05	Buddy Strings	Check if Grid can be Cut into Sections	Find All People With Secret	Square Root Convergents Spiral Primes
Day 28	2026-01-04	Swap Sex of Employees	Count Sorted Vowel Strings	Zuma Game	Lychrel Numbers Powerful Digit Sum
Day 27	2026-01-03	Kth Missing Positive Number	Maximum Length of Subarray With Positive Product	Number of Beautiful Integers in the Range	Combinatoric Selections Poker Hands
Day 26	2026-01-02	Goat Latin	Minimum Elements to Add to Form a Given Sum	Longest Subsequence Repeated k Times	Prime Digit Replacements Permuted Multiples
Day 25	2026-01-01	Latest Time by Replacing Hidden Digits	Non-decreasing Array	Length of the Longest Increasing Path	Problem 49 Problem 50
Day 24	2025-12-31	Decode XORed Array	Apply Operations to Make Sum of Array Greater Than or Equal to k	Cat and Mouse II	Distinct Primes Factors Self Powers
Day 23	2025-12-30	Arranging Coins	Minimum Deletion Cost to Make All Characters Equal	Distinct Subsequences	Triangular, Pentagonal, and Hexagonal Goldbach's Other Conjecture
Day 22	2025-12-29	Maximum Sum With Exactly K Elements	Difference Between Ones and Zeros in Row and Column	Number of Flowers in Full Bloom	Problem 43 Problem 44
Day 21	2025-12-28	Intersection of Two Arrays	Maximum Absolute Sum of Any Subarray	Count K-Reducible Numbers Less Than N	Pandigital Prime Coded Triangle Numbers
Day 20	2025-12-27	Two Sum IV - Input is a BST	Minimum Number of Operations to Have Distinct Elements	Max Value of Equation	Integer Right Triangles Champernowne's Constant
Day 19	2025-12-26	Check if The Number is Fascinating	Matchsticks to Square	Shortest Matching Substring	Truncatable Primes Pandigital Multiples
Day 18	2025-12-25	Binary Prefix Divisible By 5	Maximum Ice Cream Bars	Count the Number of Houses at a Certain Distance II	Circular Primes Double-base Palindromes
Day 17	2025-12-24	Rename Columns	Rotting Oranges	Find the Occurrence of First Almost Equal Substring	Digit Cancelling Fractions Digit Factorials
Day 16	2025-12-23	Word Pattern	Construct the Longest New String	Longest Happy Prefix	Coin Sums Pandigital Products
Day 15	2025-12-22	Longer Contiguous Segments of Ones than Zeros	Lexicographically Smallest Equivalent String	Count of Integers	Distinct Powers Digit Fifth Powers
Day 14	2025-12-21	Leaf-Similar Trees	Count and Say	Count Subarrays With Score Less Than K	Quadratic Primes Number Spiral Diagonals
Day 13	2025-12-20	Maximum 69 Number	Find Unique Binary String	Find the Number of Ways to Place People II	$1000$-digit Fibonacci Number Reciprocal Cycles
Day 12	2025-12-19	Check if Number Has Equal Digit Count and Digit Value	House Robber III	Count Connected Components in LCM Graph	Non-Abundant Sums Lexicographic Permutations
Day 11	2025-12-18	Count Distinct Numbers on Board	Find the Largest Area of Square Inside Two Rectangles	Minimum Number of Valid Strings to Form Target II	Amicable Numbers Names Scores
Day 10	2025-12-17	Project Employees I	Longest Mountain in Array	Partition Array for Maximum XOR and AND	Counting Sundays Factorial Digit Sum
Day 9	2025-12-16	Minimum Operations to Collect Elements	Employee Importance	Minimize Deviation in Array	Number Letter Counts Maximum Path Sum I
Day 8	2025-12-15	Number of Bit Changes to Make Two Integers Equal	Digit Operations to Make Two Integers Equal	Merge Operations for Minimum Travel Time	Lattice Paths Power Digit Sum
Day 7	2025-12-14	Consecutive Characters	Insert Interval	Count Distinct Subarrays Divisible by K in Sorted Array	Large Sum Longest Collatz Sequence

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