1. 每次找剩下序列中的最大值,可以进行pancake sort,时间复杂度是O(n^2): 2. 求最少交换次数进行pancake sort的问题是个NP问题,搜索的时候,upper bound是2(n-1)次,而lowwer bound(即至少需要的步数)是剩下的序列中相邻两个元素不是排好序的个数,根据上面的两个bound可以进行剪纸,也可以考虑寻找状态重复情况,不过当n比较大时,就没有办法记录了吧: 3. 若Flip的复杂度是O(1),则可以使用插入排序的算法,遍历序列中的元素,然后在排好…

计算机视觉中的边缘检测   边缘检测是计算机视觉中最重要的概念之一.这是一个很直观的概念,在一个图像上运行图像检测应该只输出边缘,与素描比较相似.我的目标不仅是清晰地解释边缘检测是怎样工作的,同时也提供一个新而又容易的方法只需要最小工作来明显地提高边缘检测. 通过获得这些边缘,许多计算机算法才得以有可能实现,因为在一个场景中边缘包含着绝大部分(至少很多)的信息. 举个例子,我们都记得 Windows XP 的那个绿色小山坡和蓝色天空的背景. 当我们的大脑试图去理解这个场景时,我们知道这是草地,看…

Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first k elements of A.  We want to perform zero or more pancake flips (doing them one after another in succession) to sort t…

Difficulty: Medium Problem Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first k elements of A. We want to perform zero or more pancake flips (doing them one after anothe…

Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first k elements of A.  We want to perform zero or more pancake flips (doing them one after another in succession) to sort t…

Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first kelements of A.  We want to perform zero or more pancake flips (doing them one after another in succession) to sort th…

时间限制:1 秒 内存限制:32 兆 特殊判题:是 提交:265 解决:116 题目描述: We start with a stack n of pancakes of distinct sizes. The problem is to convert the stack to one in which the pancakes are in size order with the smallest on the top and the largest on the bottom. To do…

排序基础 排序方法分两大类,一类是比较排序,快速排序(Quick Sort).归并排序(Merge Sort).插入排序(Insertion Sort).选择排序(Selection Sort).希尔排序(Shell Sort).堆排序(Heap Sort)等属于比较排序方法,比较排序方法理论最优时间复杂度是O(nlogn),各方法排序过程和原理见  可视化过程. 另一类是非比较排序,被排序元素框定范围的前提下可使用非比较排序方法,例如桶排序(Bucket Sort).计数排序(Counting…

Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first k elements of A.  We want to perform zero or more pancake flips (doing them one after another in succession) to sort t…

题目如下: Given an array A, we can perform a pancake flip: We choose some positive integer k <= A.length, then reverse the order of the first k elements of A.  We want to perform zero or more pancake flips (doing them one after another in succession) to…