• 4.1 name attribute of function


    About the function name attribute, different declaration methods are different, there is no rule, you can only remember it by rote  

  • C practical exercise topic 23 – printing diamond pattern


    Title:Print the following pattern (diamond). * *** ***** ******* ***** *** * Program analysis:Firstly, the graph is divided into two parts: the first four lines have a rule, and the last three lines have a rule. Using the double for loop, the first level controls the row and the second level controls the column. example: […]

  • What is the most popular application background data in wechat?


    People often use the word “overnight hit” to describe stars being famous, but such star products often appear in social networks. In the first half of 2015, “Zuji”, which just entered the social network, triggered a frenzy of sharing among wechat friends and became a popular app.So, how are the “fans” behind these star apps […]

  • How to write regular expression to verify the format of mobile phone number


    1、 Access to the mobile phone number segments of the three major operators in China Segment address As shown in the figure above, we can write regular rules according to the number segments of different operators, and also can write unified verification. I mainly write unified verification here. 2、 Ideas 1. In order to get […]

  • Data exploration of machine learning — data feature analysis (Pareto analysis)


    Pareto analysis, or contribution analysis, looks for a small number of key or decisive factors in all factors. There is a common law, the 28 law. All walks of life are interpreting its profound meaning:For example:1. 80% of the company’s profits come from 20% of the best-selling products, while the other 80% of the products […]

  • 56. Consolidation interval


    Given a set of intervals, please merge all overlapping intervals. Example 1: Input: [[1,3], [2,6], [8,10], [15,18]]Output: [[1,6], [8,10], [15,18]]Explanation: the intervals [1,3] and [2,6] overlap and merge them into [1,6]Example 2: Input: [[1,4], [4,5]]Output: [[1,5]]Explanation: the intervals [1,4] and [4,5] can be regarded as overlapping intervals. The main purpose is to find out the […]

  • On the understanding of recursive algorithm


    Recursion: The so-called recursion means that there are both transmission and regression. It is better to understand that it is a kind of “progressive” and “regular constraint” than to say that it is transmission and regression. Why do we say this? Compared with loop, recursion algorithm is more concise and clear in code structure. Recursion […]