Write a program to check whether a given number is an ugly number.

Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 2^31 - 1.

Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher’s h-index.

Given an array of citations sorted in ascending order (each citation is a non-negative integer) of a researcher, write a function to compute the researcher’s h-...

Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, …) which sum to n.

Your task is to calculate a^b mod 1337 where a is a positive integer and b is an extremely large positive integer given in the form of an array.

You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.

Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n.

Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1’s in their binary representation and return them...

Given a positive integer num, write a function which returns True if num is a perfect square else False.