Robina Li

Write an efficient algorithm that searches for a value target in an m x n integer matrix. This matrix has the following properties:

Given an array of integers nums, sort the array in ascending order and return it.

A city’s skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. Given the locations and heights of all...

You are given an array of strings equations that represent relationships between variables. Each string equations[i] is of length 4 and takes one of two different forms: "xi==yi" or "xi!=yi"....

Given an integer n, return the number of structurally unique BST’s (binary search trees) that have exactly n nodes with values from 1 to n.

Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s.

This is a classic backtracking problem that requires generating all possible combinations of k numbers chosen from the range [1, n]. The key insight is using DFS with backtracking to...

An n-bit gray code sequence is a sequence of 2^n integers where:

Given an m x n matrix, return all elements of the matrix in spiral order.

Implement pow(x, n), which calculates x raised to the power n (i.e., x^n).