摘要：
Reordered Power of 2 (M) 题目 Starting with a positive integer N, we reorder the digits in any order (including the original order) such that the leadin 阅读全文
摘要：
Design Underground System (M) 题目 Implement the class UndergroundSystem that supports three methods: 1. checkIn(int id, string stationName, int t) A cu 阅读全文
摘要：
Keys and Rooms (M) 题目 There are N rooms and you start in room 0. Each room has a distinct number in 0, 1, 2, ..., N-1, and each room may have some key 阅读全文
摘要：
Generate Random Point in a Circle (M) 题目 Given the radius and x-y positions of the center of a circle, write a function randPoint which generates a un 阅读全文
摘要：
Best Time to Buy and Sell Stock with Transaction Fee (M) 题目 You are given an array prices where prices[i] is the price of a given stock on the ith day 阅读全文
摘要：
Encode and Decode TinyURL (M) 题目 Note: This is a companion problem to the System Design problem: Design TinyURL. TinyURL is a URL shortening service w 阅读全文
摘要：
Swapping Nodes in a Linked List (M) 题目 You are given the head of a linked list, and an integer k. Return the head of the linked list after swapping th 阅读全文
摘要：
Binary Trees With Factors (M) 题目 Given an array of unique integers, arr, where each integer arr[i] is strictly greater than 1. We make a binary tree u 阅读全文
摘要：
Check If a String Contains All Binary Codes of Size K (M) 题目 Given a binary string s and an integer k. Return True if every binary code of length k is 阅读全文
摘要：
Add One Row to Tree (M) 题目 Given the root of a binary tree, then value v and depth d, you need to add a row of nodes with value v at the given depth d 阅读全文