Longest Arithmetic Subsequence with Difference Constraint
Given a list of integers nums and an integer diff, return the length of the longest arithmetic subsequence where the difference between each consecutive numb...
Posts with tag 'math'
Airplane Seat Shuffling
You are given an integer n representing the number of seats in an airplane. The first person has lost their ticket, so they pick a random seat. Everyone else...
Count of Sublists with Same First and Last Values
Given a list of integers nums, return the number of sublists where the first element and the last element have the same value.
Count Substrings With All 1s
You are given a string s containing "1"s and "0"s. Return the number of substrings that contain only "1"s. Mod the result by 10 ** 9 + 7.
Ugly Number
Given an integer n, return whether its prime factors only include 2, 3 or 5.
Sum of the Digits
Given a positive integer num, return the sum of its digits.
Sum of First N Odd Integers
Given an integer n, return the sum of the first n positive odd integers.
Search in a Virtually Complete Binary Tree
Consider a complete binary tree of n nodes whose values are 1 to n. The root has value of 1, its left child is 2 and its right child is 3. In general, nodes’...
Prime Factorization
You can write out a number as a product of prime numbers, which are its prime factors. The same prime factor may occur more than once.
Palindromic Integer
Given a non-negative integer num, return whether it is a palindrome.
N-Rooks
You’ve got an integer n representing a chessboard of size n x n. Return the number of ways you can place n rooks, such that no two rooks attack each other.
Median Minimization
Given a list of integers nums, split it into two lists of equal size where the absolute difference between each list’s median is as small as possible and ret...
List Equality with Increments
You are given a list of integers nums, and want to make the values equal. Consider an operation where you pick an integer in the list and increment every oth...
Linked List to Integer
Given a single linked list node, representing a binary number with most significant digits first, return it as an integer.
Line Segment
Given a list of [x, y] coordinates in a Cartesian plane, return whether the coordinates form a straight line segment.
Line of People
You are given integers n, a and b. You are standing in a line of n people. You don’t know which position you’re in, but you know there are at least a people ...
Integer to Base 3
Given an integer n, return its base 3 representation as a string.
Guess the Root
Given a non-negative integer n, find a number r such that r * r = n and round down to the nearest integer.
Greatest Common Divisor
Given a list of positive integers nums, return the largest positive integer that divides each of the integers.
Generate Primes
Given a number n, return a list of all prime numbers smaller than or equal to n in ascending order.
First to Count to Target
You are playing a game against a friend where in each round you pick a number from 1 to k to add to a shared running total that initially starts from 0. The ...
Factorial Sum
Given a positive integer n, return whether n can be written as the sum of distinct positive factorial numbers.
Detect the Only Duplicate in a List
You are given a list nums of length n + 1 picked from the range 1, 2, ..., n. By the pigeonhole principle, there must be a duplicate. Find and return it. The...
Complete an Arithmetic Sequence
You are given a list of integers nums that used to be an arithmetic sequence. Given that a number was removed, and that the number was not the first or the l...
Clock Angle
Given a clock time with hour and integer minutes, determine the smaller angle between the hour and the minute hands and floor it to the nearest integer.
Check if Number Is Perfect Square
Given an integer n, return whether n = k * k for some integer k.
Base 3 to Integer
Given a string s representing a number in base 3 (consisting only of 0, 1, or 2), return its decimal integer equivalent. This should be implemented directly ...