2018年8月8日
Andrew Ng-ML-第十二章-机器学习系统设计
摘要： 1.确定执行的优先级 图1.邮件垃圾分类举例 选择100个单词作为指示是否是垃圾邮件的指标，将这些单词作为特征向量，只用0/1表示，出现多次也只用1表示，特征变量用来表示邮件。 通常情况下，会选择训练集中出现频率最多的n(在10000到50000)之间的几个单词。 图2.改进模型的建议 1.收集更多 阅读全文
posted @ 2018-08-08 19:35 lypbendlf 阅读(157) 评论(0) 推荐(0) 编辑
PAT 1028 List Sorting[排序][一般]
摘要： Excel can sort records according to any column. Now you are supposed to imitate this function. Input Each input file contains one test case. For each 阅读全文
posted @ 2018-08-08 13:38 lypbendlf 阅读(152) 评论(0) 推荐(0) 编辑
PAT 1027 Colors in Mars[简单][注意]
摘要： People in Mars represent the colors in their computers in a similar way as the Earth people. That is, a color is represented by a 6-digit number, wher 阅读全文
posted @ 2018-08-08 12:24 lypbendlf 阅读(124) 评论(0) 推荐(0) 编辑
PAT 1026 Table Tennis[比较难]
摘要： A table tennis club has N tables available to the public. The tables are numbered from 1 to N. For any pair of players, if there are some tables open 阅读全文
posted @ 2018-08-08 11:49 lypbendlf 阅读(164) 评论(0) 推荐(0) 编辑
2018年8月7日
1025 PAT Ranking［排序］［一般］
摘要： Programming Ability Test (PAT) is organized by the College of Computer Science and Technology of Zhejiang University. Each test is supposed to run sim 阅读全文
posted @ 2018-08-07 19:10 lypbendlf 阅读(137) 评论(0) 推荐(0) 编辑
PAT 1023 Have Fun with Numbers[大数乘法][一般]
摘要： Notice that the number 123456789 is a 9-digit number consisting exactly the numbers from 1 to 9, with no duplication. Double it we will obtain 2469135 阅读全文
posted @ 2018-08-07 17:22 lypbendlf 阅读(163) 评论(0) 推荐(0) 编辑
Andrew Ng-ML-第十章-应用机器学习的建议
摘要： 1.如何改进性能不好的学习算法 图1.运用到测试集上效果不佳 当进行一个正则化线性回归时，最小化了代价函数得到参数，但是运用到新的测试集上，发现效果不好，那么如何改进？ 1).增加训练集。但是实际上花费的时间更多，效果并不好。 2).选取更小的特征集合。 3).获取更多特征。 4).加入多项式特征项 阅读全文
posted @ 2018-08-07 15:49 lypbendlf 阅读(153) 评论(0) 推荐(0) 编辑
Andrew Ng-ML习题答案1
摘要： 1.Linear Regression with Multiple Variables 转自：https://blog.csdn.net/mupengfei6688/article/details/53098735 1.Suppose m=4 students have taken some cla 阅读全文
posted @ 2018-08-07 08:54 lypbendlf 阅读(364) 评论(0) 推荐(0) 编辑
2018年8月6日
PAT 1022 Digital Library[map使用]
摘要： A Digital Library contains millions of books, stored according to their titles, authors, key words of their abstracts, publishers, and published years 阅读全文
posted @ 2018-08-06 17:53 lypbendlf 阅读(265) 评论(0) 推荐(0) 编辑
PAT 1021 Deepest Root[并查集、dfs][难]
摘要： A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the 阅读全文
posted @ 2018-08-06 16:34 lypbendlf 阅读(145) 评论(0) 推荐(0) 编辑