Given two non-negative integers represented as strings, return their product as a string. You must not use any built-in BigInteger library or convert the inputs to integers directly.
Given an n x n 2D matrix representing an image, rotate the image by 90 degrees clockwise. The rotation should be done in-place, meaning you cannot allocate another 2D matrix.
You are given a number x and an integer n. Your task is to compute x raised to the power n (i.e., x^n). Handle cases where the exponent is negative by returning the reciprocal of the result.
A robot starts at the top-left corner of an m x n grid and can only move right or down. Determine the total number of unique paths it can take to reach the bottom-right corner.
You are given a large integer represented as an array of digits. Each digits[i] represents the ith digit of the integer, arranged from most significant to least significant. The task is to increment the integer by one and return the resulting digits as an array.
