摘要：1. 在JAVA中，对象的分配一般使用new关键字。　当虚拟机遇到new指令时，会先检查该指令所包含的参数在常量池中能否找到一个符号引用，并检查该符号引用所代表的类是否被加载、解析和初始化。 如果没有，则会先执行类的加载过程。2. 类加载完成后，会为该对象分配内存空间。一个对象需要多大的内存空间在... 阅读全文

摘要：Given a 2D board and a list of words from the dictionary, find all words in the board.Each word must be constructed from letters of sequentially adjac... 阅读全文

摘要：There are two sorted arraysnums1andnums2of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should... 阅读全文

摘要：Given an unsorted array, find the maximum difference between the successive elements in its sorted form.Try to solve it in linear time/space.Return 0 ... 阅读全文

摘要：Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given[100, 4, 200, 1, 3, 2],The longest ... 阅读全文

摘要：Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A solution using O(n) space is ... 阅读全文

摘要：Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximu... 阅读全文

摘要：The set[1,2,3,…,n]contains a total ofn! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie... 阅读全文

摘要：Given a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially adjacent cell, where "adjace... 阅读全文

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

摘要：1. 先序遍历public void preorder(TreeNode root) { if(root == null) return; Stack stack = new Stack(); while(true) { if(root... 阅读全文