To describe supervised learning,we establish notation for future use.
**$x^i$ **denote the input variables also called input features
**$y^i$ ** denote the output variables also called target variables that we are trying to predict.
A pair **($x^i, y^i$) **is called a training set.
we just find the position of the character '.' and '/' and '%' and reverse the string before and after the character and omit the front zeros.
Every time I use find function in C++ , I always search its usage after using it for so many times. So I decide to make a summary of some commonly used usages.
KMP is an algorithm that find the given pattern string in the pending string. Usually we would think of violent traversing the two strings using for loop. However the time complexity of this method is O(n)~O(mn). So the KMP can cut the times of loop.
Because of my first theme was so incomplete that I need to add many features myself. So I’ve looked for how to add comment system on the blog.
Last time I‘ve talked about how to build your own blog, however, the original theme might not very beautiful to you. So this time I would write how to change your blog theme and others.
In combinatorics (combinatorial mathematics), the inclusion–exclusion principle is a counting technique which generalizes the familiar method of obtaining the number of elements in the union of two finite sets; – From Wikipedia
Today’s importance is inverse element, however, inverse element calculation is based on the extended Euclid algorithm. At first, we need to know the Euclid’s algorithm.
