k-means

K-means是一种聚类算法: 这里运用k-means进行31个城市的分类 城市的数据保存在city.txt文件中,内容如下: BJ,2959.19,730.79,749.41,513.34,467.87,1141.82,478.42,457.64TianJin,2459.77,495.47,697.33,302.87,284.19,735.97,570.84,305.08HeBei,1495.63,515.90,362.37,285.32,272.95,540.58,364.91,188.63

k-means是一种非监督 (从下图0 当中我们可以看到训练数据并没有标签标注类别)的聚类算法 0.initial 1.select centroids randomly 2.assign points 3.update centroids 4.reassign points 5.update centroids 6.reassign points 7.iteration reference: https://www.naftaliharris.com/blog/visualizing-k-me

1.题目分析: 查找无序数组中的第K大数,直观感觉便是先排好序再找到下标为K-1的元素,时间复杂度O(NlgN).在此,我们想探索是否存在时间复杂度 < O(NlgN),而且近似等于O(N)的高效算法. 还记得我们快速排序的思想麽?通过“partition”递归划分前后部分.在本问题求解策略中,基于快排的划分函数可以利用“夹击法”,不断从原来的区间[0,n-1]向中间搜索第k大的数,大概搜索方向见下图: 2.参考代码: 1 #include <cstdio> 2 3 #define sw

Game Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1065    Accepted Submission(s): 449 Problem Description onmylove has invented a game on n × m grids. There is one positive integer on each g

Misaki's Kiss again Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 201    Accepted Submission(s): 57 Problem Description After the Ferries Wheel, many friends hope to receive the Misaki's kiss

RXD, tree and sequence Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 234    Accepted Submission(s): 82 Problem Description RXD has a rooted tree T with size n, the root ID is 1, with the dep

在开发或者测试的过程中,我们可以通过 adb 来管理多台设备,其一般的格式为: adb [-e | -d | -s <设备序列号>] <子命令> 在配好环境变量的前提下,在命令窗口当中输入 adb help 或者直接输入 adb ,将会列出所有的选项说明及子命令.这里介绍一些里面常用的命令: 1 adb devices , 获取设备列表及设备状态 2 [xuxu:~]$ adb devices 3 List of devices attached 4 44c826a0 device

Buy the souvenirs Time Limit: 10000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1886    Accepted Submission(s): 699 Problem Description When the winter holiday comes, a lot of people will have a trip. Genera

对于数据科学来说,现在是发展的黄金时期.这是个新领域,但增长迅速,同时数据科学家的缺口也很大,据说他们的平均年薪可以达到10万美元.哪里有高薪,哪里就吸引人们,但是数据科学技能的差距意味着许多人需要努力学习.      第一步当然是询问“我怎么学习数据科学”,这个问题的答案往往是一长串的课程和书籍阅读,从线性代数到统计数据,这几年我也是这样学习过来的.我没有编程背景,但我知道我喜欢处理数据. 我比较不能理解在完全没有理解别人的背景时就给他一份长长的书单或者技能表.这就类似于一个老师给你一堆教科书

Description: You are given a matrix which is n rows m columns (1 <= n <= m <= 100). You are supposed to choose n elements, there is no more than 1 element in the same row and no more than 1 element in the same column. What is the minimum value of