一、概念 什么是JXL Jxl是一个开源的Java Excel API项目,通过Jxl,Java可以很方便的操作微软的Excel文档。除了Jxl之外,还有Apache的一个POI项目,也可以操作Excel,两者相比之下:Jxl使用方便,但功能相对POI比较弱。POI使用复杂,上手慢,除了这个没啥说的了。 二、特点 可以对Excel表格进行创建/删除,还有增删改查等操作 三、使用 1. 创建Exce

Android Studio   java   jxl  

一、分类 1、二叉查找树 (1)左子树不为空,并且左子树所有结点的值小于根节点的值 (2)右子树不为空,并且右子树所有节点的值大于根节点的值 (3)左右子树也分别是二叉排序树 (4)没有键值相等的结点 2、平衡二叉树(AVL) 左右两个子树的高度差不超过一,并且左右两个子树也都是平衡二叉树 3、红黑树 (1)每个结点要么是红的要不是黑的 (2)根结点必须是黑的 (3)叶子结点必须是黑的 (4)如果

java   二叉树   总结   面试   笔试  

一、原题 Clone an undirected graph. Each node in the graph contains alabeland a list of itsneighbors. OJ's undirected graph serialization: Nodes are labeled uniquely. We use#as a separator for each node,

LeetCode   java   DFS   BFS  

一、原题 There are N gas stations along a circular route, where the amount of gas at station i isgas[i]. You have a car with an unlimited gas tank and it costscost[i]of gas to travel from station i to its

java   LeetCode  

一、原题 There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following requirements: Each child must have at least one

LeetCode   java   小朋友分糖  

一、原题 Given an array of integers, every element appears three times except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without us

LeetCode   java   位与  

一、原题 A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null. Return a deep copy of the list. 一、中文 链表的每个元素不仅有指向下一个结点的指针,还包括了一

LeetCode   java   单链表   深拷贝  

一、原题 Given a binary tree, determine if it is height-balanced.  For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never di

LeetCode   java   二叉树  

一、原题 Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).  For example:  Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 1

遍历   LeetCode   java  

一、原题 Given a binary tree, return the inorder traversal of its nodes values.  一、中文 二叉树的前序、中序、后序三种遍历方式的总结 三、举例 前序:根-左-右 中序:左-根-右 后序:左-右-根 四、思路   每一种遍历方式都有两种方式,一种是递归,一种是非递归的方式,递归很简单,下面主要是非递归的方式 (1)前序 首先建

LeetCode   java  
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