摘要： 题目：Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.解题思路1：设置一个变量存储当前记录下的最小深度，采用先序遍历的方法访问树的每一个节点，设置一个变量表示当前节点所在的层次，如果一个节点没有子节点，那么就比较该节点的深度与当前的最小深度，选择两者之中较小的作为当前的最小深度。代码：/** * Definition for bi 阅读全文

摘要： 题目：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 ofeverynode never differ by more than 1.解题思路1（下面给出两种代码实现，代码1和代码2）：采用递归的方法，对每一层的节点进行遍历，从叶子节点开始回溯，并从下往上判断每一层的各个是否满足平衡树的条件，并得到以该节 阅读全文

摘要： 题目：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \3 4 4 3But the following is not: 1 / \ 2 2 \ \ 3 3Note:Bonus points if you could solve it both recursively and iter... 阅读全文

摘要： 题目：Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical and the nodes have the same value.解题思路：对两棵树进行遍历即可，这里采用先序遍历的方法。代码：/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *... 阅读全文

摘要： 题目：Given a sorted linked list, delete all duplicates such that each element appear onlyonce.For example,Given1->1->2, return1->2.Given1->1->2->3->3, return1->2->3.解题思路：设置两个指针CurrList和NewList，初始化为同一头指针，CurrList不断向链表尾部扫描，如果当前节点的值不是重复值，就将该节点接到NewList尾部。代码：/** * Definition for 阅读全文

摘要： 题目：Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit is at the head of the list.解题思路：要给原有容器表示的数加1，主要需要处理的就是进位的问题。由于是加1，因此只有在当前数字为9的时候采进位。如果在数组的第0个元素上还需要进位，那么就需要在该元素前面增加一个数字1。代码：class Solution {public: v... 阅读全文

摘要： 题目：Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't matter what you leave beyond the new length.解题思路：设置两个指针pa,pb，pa指针从0开始依次向n-1滑动，当pa指向的元素不是待删除的元素时，将pa指向的元素赋给pb指向的元素，同时pb向前滑动。代码：class Solution {publ 阅读全文

摘要： 题目：Follow up for "Search in Rotated Sorted Array":What ifduplicatesare allowed?Would this affect the run-time complexity? How and why?Write a function to determine if a given target is in the array.解题思路：该题与Search in Rotated Sorted Array的主要区别在于需要考虑A[low]与A[mid]相等、A[mid]与A[high]相等以及A[low]A[m 阅读全文

摘要： 题目：Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e.,0 1 2 4 5 6 7might become4 5 6 7 0 1 2).You are given a target value to search. If found in the array return its index, otherwise return -1.You may assume no duplicate exists in the array.解题思路：数组的查找一般可以使用二分查找法，但是这道题里的 阅读全文

摘要： 假设现在我需要在Beacon帧中添加一个字段，应该如何添加呢？我们首先来看一看Beacon帧的帧结构（我们需要在Frame Body的保留字段进行字段的添加）：Beacon帧是管理帧的一种，管理帧使用信息元素（informationelement，带有数字标签的数据块）来与其他系统交换信息。信息元素是管理帧的可变长组件。信息元素通常包含一个ElementID（元素标识符）字段、一个Length（长度）字段以及一个长度不定的字段，如图所示：查阅802.11规定的信息元素表可以发现，编号为7-15（OpenWRT程序中是8-15）的信息元素是未使用的保留元素，因此可以在Beacon帧中加入该编号范 阅读全文