This is a non-technical blog, but to me it carries a lot of value
On an ordinary and quiet day, I was hit by a message, so I wrote a sharing post to commemorate my 1460 days of persistence in my original intention:
Foreword: A look back at the past
Four years ago, I was in my sophomore year. For a 计算机科学与技术professional student, freshman and sophomore year are the most stressful period of course:
- Non-professional core compulsory courses: "Advanced Mathematics", "Linear Algebra", "Probability Theory", and the most outrageous "University Physics". These courses cannot be passed, and if you still want to get a scholarship or graduate school, you have to try your best to get a high score;
- Major core compulsory courses: "Algorithm and Data Structure", "Discrete Mathematics", "Programming C/C++ Language", "Database Principles", "Computer Network", "Object-Oriented C++", "Advanced Programming Language Java", "Big Data Analysis Language Python" ", and the most outrageous "Digital Circuit Design" and "Analog Circuit Design" (I still don't understand why in our school, students majoring in computer science should learn digital electronics, analog electronics, and students of electronic information should learn algorithms and data structures and operating system). Of course, we are juniors who are familiar with hell courses such as "Operating System", "Compiler Principles", and "Numerical Analysis". . .
Of course, there is also course practice at the end of each semester (that is, to do a project and write an experimental report), from the initial console application (C/C++) to desktop application (Java, Qt), to mobile application development, web application program……
To be honest, those four years of undergraduate studies were really tough, but whenever I think about it, I really miss it. I miss that time when I knew nothing but had clear goals; I miss that time when I was vigorous and hard-working; I miss all my roommates at that time, we went to school together, typed codes, and stayed up late on weekends to score points...
Opportunity: Meet CSDN
The first time I came into contact with CSDN was five years ago (when I was a freshman). At that time, I participated in the Blue Bridge Cup Programming Contest. Since the teacher had to assign questions on the OJ of the Blue Bridge official website every week, the weekend at that time was my Question time. What's interesting is that I hadn't taken the "Algorithm and Data Structure" course at this time (this course was only offered in my sophomore year), so for a pure algorithm novice, Zhou Lian was teaching me how to do things almost every week.
The first time I wrote down CSDN came from a question related to DFS. During the preparation period, our school’s training teachers would talk about a lot of algorithms. In a class about depth-first search, I sat at the back of the classroom because I came late. And I am a little short-sighted, which caused me to fail to understand this knowledge point. So I opened Baidu to search for "Depth First Search DFS". At the moment I clicked Enter, several entries popped up on the web page, but I found that there was a website CSDN blog under many entries . So I Yiyi clicked on it to check, and found that the explanations were very detailed, even better than what my teacher said. So, I planted an idea in my mind: "Let's find all computer-related problems here in the future."
Resolution: Become a Blogger
This determination originates from a data structure "union check".
At that time, I encountered a problem in the Blue Bridge Cup system ( [Blue Bridge Cup] The troubles of the king of previous test questions ). I thought about it for a few days and didn’t understand what was going on. A data structure: union search . So I spent a long time gnawing at this knowledge point, and after mastering the data structure, I went back and continued to solve this problem, and finally solved it.
For many students who participated in the ACM competition, I believe that when you see the test data flashing green and the final AC, you will be very happy in your heart! I was the same, I felt that the whole world was bright that afternoon. In addition, I have a good habit: I will record my solution ideas in a document. So, I recorded the solution idea of this question and the construction and execution principle of the data structure of merge search:
This habit later allowed me to post 55 high-quality algorithm solutions within one year in 2020 (I will write the solutions separately, all of which I think are worthwhile and have a certain degree of difficulty).
I have a very deep image of it. That day 【蓝桥杯】 历届试题 国王的烦恼when AC was this question, I was teaching a class ("Marxist Philosophy"). My roommate and I were sitting on the side near the door at the back of the classroom. I was so excited at the time. A few days before I started to do this question, when I worked hard to find no results, I checked the relevant solutions on CSDN, but almost all of them were all descriptions of questions + codes, without any ideas at all (and Many people are hydrologists, they copied it from others and posted it themselves). So when I took this question with AC, I suddenly had an idea: why don't you try to write a solution?
So, I completed my first blog in the class of Marxist philosophy: [Blue Bridge Cup] The troubles of the king of previous test questions (and check) . To be honest, I still remember the feeling now, very comfortable, as if I had accomplished a big event. Therefore, that night, I specially rewarded myself to go to the scholarly town to have a casserole of fatty intestines and potatoes.
At that time, I set my original intention in CSDN: to be a high-quality blog post producer.
reward
Before I knew it, 4 years passed, which is the study period of a college student, and it seems so fast now.
In those 4 years, no more, no less, 101 original articles have just been published. In these articles, I list some of my personal favorites (columns):
- The widely acclaimed article is also my personal starting point: [Algorithms and Data Structures] - and check
- Perfect deduction, extreme reasoning, and an explanation that shows the beauty of mathematics: [Machine Learning] Support Vector Machine
- Excellent blog post with strict logic and double show of pictures and texts: [Machine Learning] Decision Tree
- Personally think the best solution: [Blue Bridge Cup] Algorithm Improvement Jinling Thirteen Hairpins
- Explanation of data structure combining theory and practice: 【Algorithm and Data Structure】—— prefix sum and difference
- The practice of machine learning algorithms combining theory and practice: [Machine Learning] Clustering Algorithms (Practical Combat)
- Ingenious column: 【Machine Learning】
In these 4 years, I have gained 1710 fans, 3118 likes, and 6697 favorites (as of writing this post). I am very happy that so many people affirm and recognize me, encourage and support me, this is the greatest certification for my creation! ! ! So, here is my sincere thanks to all my fans:
At the same time, I would like to assure you that I will continue to create in the future and provide you with high-quality blog posts.
Note: At present, the blogger is studying for a master's degree, and the direction is cluster analysis. The future articles will mainly tend to: machine learning, paper interpretation, algorithm related (pure love).
Achievement
-
The best solution and code written in the past
It is none other than [Blue Bridge Cup] Algorithm Improvement Jinling Shisanchai . In this question, I feel the beauty of code and the fun of programming:
#include<iostream>
using namespace std;
const int N=14;
int like[N][N],dp[1<<N];
void create(int n) //录入like数组
{
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
cin>>like[i][j];
}
int lowbit(int n){
return n&(-n); } //取出最低位1所表示的数
int getOneCount(int n) //得到数n的二进制表达式中1的个数
{
int num=0;
while(n){
num++;
n -= lowbit(n);
}
return num;
}
void DP(int n)
{
for(int i=1;i<(1<<n);i++){
//枚举所有配对序列state（如11010、11000、10010、01010等）
for(int j=0;j<n;j++) //枚举所有的单1序列state1（如00001、00010、00100等）
if(i & (1<<j)) //如果当前的单1序列state1是由原始state得来（如01010、10010、11000能由11010得来）才能进行下面的动态转移
dp[i]=max(dp[i],dp[i-(1<<j)]+like[getOneCount(i)][j+1]);
}
}
int main()
{
int n;cin>>n;
create(n);
DP(N);
cout<<dp[(1<<n)-1]<<endl;
return 0;
}
Personally, I really like the language C++, she is really beautiful.
- 【Big Data Platform Technology】Column : 【Big Data Platform Technology】
- [Horseshoe Collection Test Questions] Column : [Horseshoe Collection Test Questions Solution]
- 【Machine Learning】Column : 【Machine Learning】
look forward to
My biggest dream is to work in a major Internet company.
Finally, I would like to give myself and my colleagues in the computer industry a word: love programming, love life, and love everything you have.
Tips
- The articles you publish will be displayed in the milestone area , and you can also view other creators' anniversary articles in the area
- High-quality commemorative articles will receive mysterious rewards