Title: Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white,…

列表是一列按特定顺序排列的元素组成. 在Python中,用方括号[]来表示列表 下面是一个语言列表 Language = ['Chinese','English','Franch','Deutsch'] print(Language) 打印结果包括方括号等 ['Chinese', 'English', 'Franch', 'Deutsch'] 1.1 访问列表元素 print(Language[0]) 打印结果: Chinese 列表示通过索引来访问其值的,但是值是从0开始的,而不是1,访问倒数…

In the following, every capital letter represents some hexadecimal digit from 0 to f. The red-green-blue color "#AABBCC" can be written as "#ABC" in shorthand.  For example, "#15c" is shorthand for the color "#1155cc&quo…

Sept. 22, 2015 学一道算法题, 经常回顾一下. 第二次重温, 决定增加一些图片, 帮助自己记忆. 在网上找他人的资料, 不如自己动手. 把从底向上树的算法搞通俗一些. 先做一个例子: 9/22/2015 Go over one example to build some muscle memory about this bottom up, O(1) solution to find the root node in subtree function. Sorted List: 1…

Given a n x n matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix. Note that it is the kth smallest element in the sorted order, not the kth distinct element. Example: matrix = [ [ 1, 5…

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 twoSum should return indices of the two numbers such that they add up to the target, where index1 mu…

Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might be…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 这道寻找旋转有序数组的最小值肯定不能通过直接遍历整个数组来寻找,这个方法过于简单粗暴,这样的话,旋不…

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要求把有序链表转为二叉搜索树,和之前那道Convert Sorted Array to Binary Search Tree 将有序数组转为二叉搜索树思路完全一样,只不过是操作的数据类型有所差别,一个是数组,一个是链表.数组方便就方便在可以通过index直接访问任意一个元…

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要将有序数组转为二叉搜索树,所谓二叉搜索树,是一种始终满足左<根<右的特性,如果将二叉搜索树按中序遍历的话,得到的就是一个有序数组了.那么反过来,我们可以得知,根节点应该是有序数组的中间点,从中间点分开为左右两个有序数组,在分别找出其中间点作为原中间点的左右两个子节点,这不就是是二分查找法的核…