Topic
Math problems
140 problems: 57 easy, 58 medium, 25 hard.
Easy (57)
- Sqrt(x)
- Happy Number
- Number of 1 Bits
- Pascal's Triangle
- Maximum Depth of Binary Tree
- Invert Binary Tree
- Symmetric Tree
- Same Tree
- Diameter of Binary Tree
- Balanced Binary Tree
- Subtree of Another Tree
- Happy Number Sequence
- Count Odd Numbers in an Interval Range
- Count Negative Numbers in a Sorted Matrix
- Number of Equivalent Domino Pairs
- Special Positions in a Binary Matrix
- Maximum Units on a Truck
- Power of Three
- Power of Four
- Ugly Number
- Add Digits
- Perfect Number
- Self Dividing Numbers
- Fibonacci Number
- N-th Tribonacci Number
- Hamming Distance
- Middle of Linked List
- Minimum Depth of Binary Tree
- Count Negative Numbers in Matrix
- Truncate Sentence
- Number of Students Unable to Eat Lunch
- Count Largest Group
- Lucky Numbers in Matrix
- Cells with Odd Values
- Convert Binary Number in Linked List
- Sum of Root To Leaf Binary Numbers
- Subtract Product and Sum
- Count Odd Numbers in Range
- Smallest Even Multiple
- Maximum 69 Number
- Count Negatives in Sorted Matrix
- Maximum Depth of N-ary Tree
- Binary Watch
- Subtract Product and Sum of Digits
- Digit Square Sum
- GCD of Array
- Nim Take Stones
- Count Divisors
- Product of Nonzero Digits
- Fibonacci Modulo
- Sum Even Minus Odd Digits
- Sum of Digits
- Is Power of Two
- Is Perfect Square
- Greatest Common Divisor
- Least Common Multiple
- Sum of Multiples of 3 or 5
Medium (58)
- Count Primes
- Unique Paths
- Number of Islands
- Lowest Common Ancestor of a Binary Tree
- Clone Graph
- Add Two Numbers
- Remove Nth Node From End of List
- Factorial Trailing Zeroes
- Perfect Squares
- Odd Even Linked List
- Car Fleet
- Count Good Nodes in Binary Tree
- Binary Tree Right Side View
- Combination Sum II
- Sum of Two Integers
- Pow(x, n) - Fast Exponentiation
- Maximum Swap
- Design Leaderboard
- Binary Tree Zigzag Level Order Traversal
- Path Sum II
- Sum Root to Leaf Numbers
- House Robber III
- Delete Node in a BST
- Number of Provinces
- Ugly Number II
- Queue Reconstruction by Height
- All Nodes Distance K in Binary Tree
- Nth Digit
- Beautiful Arrangement
- Count Servers that Communicate
- Bulb Switcher III
- Flip Columns For Maximum Number of Equal Rows
- Next Greater Element III
- Add Two Numbers (Linked List)
- Swap Nodes in Pairs
- Lowest Common Ancestor of Binary Tree
- Path Sum III
- Equal Row and Column Pairs
- Count Numbers with Unique Digits
- Smallest Value After Replacing Primes
- Combination Sum III
- Battleships in a Board
- Circular Permutation in Binary
- Maximum Level Sum of a Binary Tree
- Tree Diameter
- Number of Corner Rectangles
- Number of Pairs of Interchangeable Rectangles
- Open the Lock
- Snakes and Ladders
- Rotate Function
- Josephus Survivor
- Smallest Prime Factor Sieve
- Modular Exponentiation
- Modular Inverse (Prime)
- Extended GCD
- Catalan Number
- Polygon Area (Doubled)
- Convex Hull Vertex Count
Hard (25)
- Reverse Nodes in k-Group
- Burst Balloons
- Number of Digit One
- Binary Tree Maximum Path Sum
- Number of Islands II
- Russian Doll Envelopes
- Binary Tree Cameras
- Smallest Range Covering Elements from K Lists
- Course Schedule III
- Kth Smallest Number in Multiplication Table
- Consecutive Numbers Sum
- Minimize Malware Spread
- Preimage Size of Factorial Zeroes Function
- Non-negative Integers without Consecutive Ones
- Count Ways to Build Rooms in an Ant Colony
- Sum of Euler Totient
- Count Coprime Pairs
- Miller-Rabin Primality Check
- Largest Prime Factor
- k-th Lexicographic Permutation
- Euler Totient of n
- Fast-Doubling Fibonacci Modulo
- Discrete Logarithm (BSGS)
- Chinese Remainder Theorem
- Triangle Interior Lattice Points