You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add...

Given a pattern and a string str, find if str follows the same pattern.

Given two strings s and t, write a function to determine if t is an anagram of s.

给你一个 m x n 的矩阵 matrix 。如果这个矩阵是托普利茨矩阵，返回 true ；否则，返回 false 。

Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.

You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your frie...

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

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Given a set of distinct integers, nums, return all possible subsets.

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.