摘要： 题目如下： We are given an array A of N lowercase letter strings, all of the same length. Now, we may choose any set of deletion indices, and for each stri 阅读全文

摘要： 题目如下： Given two integers n and k, you need to construct a list which contains ndifferent positive integers ranging from 1 to n and obeys the following 阅读全文

摘要： 题目如下： For a binary tree T, we can define a flip operation as follows: choose any node, and swap the left and right child subtrees. A binary tree X is  阅读全文

摘要： 题目如下： Given an array of 4 digits, return the largest 24 hour time that can be made. The smallest 24 hour time is 00:00, and the largest is 23:59. Star 阅读全文

摘要： 题目如下： In a deck of cards, every card has a unique integer. You can order the deck in any order you want. Initially, all the cards start face down (unr 阅读全文

摘要： 题目如下： All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes usef 阅读全文

摘要： 题目如下： On an NxN chessboard, a knight starts at the r-th row and c-th column and attempts to make exactly K moves. The rows and columns are 0 indexed, 阅读全文

摘要： 题目如下： There is an m by n grid with a ball. Given the start coordinate (i,j) of the ball, you can move the ball to adjacent cell or cross the grid boun 阅读全文

摘要： 题目如下： On a 2D plane, we place stones at some integer coordinate points. Each coordinate point may have at most one stone. Now, a move consists of remo 阅读全文

摘要： 题目如下： You have an initial power P, an initial score of 0 points, and a bag of tokens. Each token can be used at most once, has a value token[i], and h 阅读全文