Alan Hu

摘要： A peak element is an element that is greater than its neighbors.Given an input array wherenum[i] ≠ num[i+1], find a peak element and return its index.... 阅读全文

摘要： Given a collection of integers that might contain duplicates,S, return all possible subsets.Note:Elements in a subset must be in non-descending order.... 阅读全文

摘要： Given a set of distinct integers,S, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must not co... 阅读全文

摘要： Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree andsum =... 阅读全文

摘要： Givenn, generate all structurally uniqueBST's(binary search trees) that store values 1...n.For example,Givenn= 3, your program should return all 5 uni... 阅读全文

摘要： Givenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a total of 5 unique BST's. 1... 阅读全文

摘要： 2.4 证明对任意常数k，（称此式为公式A）证明：①当k11)时，都满足公式A，即 （k1)，若能证明，即可得证公式A成立， 根据洛比达法则，0/0型不定式极限和∞/∞型不定式极限，有： 因此对内部分数上下求导，得： ... 阅读全文

摘要： Given an arraySofnintegers, find three integers inSsuch that the sum is closest to a given number, target. Return the sum of the three integers. You m... 阅读全文

摘要： Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephon... 阅读全文

摘要： Say you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete a... 阅读全文