xiaolovewei

摘要： Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"A man, a plan, a canal: Pan 阅读全文

摘要： Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function 阅读全文

摘要： Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction 阅读全文

摘要： Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3,Return [1,3,3,1]. Note:Could you optimize your algorithm to us 阅读全文

摘要： Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return 思路：动态规划，前面的构建出来了，后面根据某种关系也就可以构建出来。 这个要根据前一行来构建下一 阅读全文

摘要： Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. F 阅读全文

摘要： 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 dept 阅读全文

摘要： 二叉堆 我们知道堆栈是一种LIFO（后进先出）结构，队列是一种FIFO（先进先出）结构，而二叉堆是一种最小值先出的数据结构，因此二叉堆很适合用来做排序。 二叉堆的性质：二叉堆是一棵完全二叉树。 二叉堆采用数组来存储（按广度优先遍历的顺序），而没有像普通的树结构使用指针来表示节点间的关系。 如下图所示 阅读全文