Given a sorted integer array without duplicates, return the summary of its ranges.

Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute d...

Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn’t one, retur...

Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.

Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.

You are given an integer array nums and you have to return a new counts array. The counts array has the property where counts[i] is the number of smaller elemen...

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume tha...

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.

Median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle va...

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.