Robina Li

You are given a string s and array queries where queries[i] = [left, right, k]. We may rearrange the substring s[left...right] and then choose up to k of its characters...

Given an integer array nums, handle multiple queries of the following type:

Given an integer array data representing the data, return whether it is a valid UTF-8 encoding (i.e., it translates to a sequence of valid UTF-8 encoded characters).

Given a 2D matrix matrix, handle multiple queries of the following types:

LeetCode wants to give one of its best employees the option to travel among n cities to collect algorithm problems. But all work and no play makes Jack a dull...

Given a rows x cols screen and a sentence represented as a list of strings, return the number of times the given sentence can be fitted on the screen.

The next greater element of some element x in an array is the first greater element that is to the right of x in the same array.

Given a sorted integer array nums and three integers a, b, and c, apply a quadratic function f(x) = ax² + bx + c to each element nums[i] in the...

A Range Module is a module that tracks ranges of numbers. Design a data structure to track the ranges represented as half-open intervals [left, right).

A word square is a sequence of words where the k-th row and k-th column read the same string.