[Java] How an inexperienced person can reach paiza B rank in 2 weeks


Our new employee training is "while learning by yourself, ask senior engineers questions that you do not understand." Although it is a style, it was set to take B rank in Paiza's skill check as an intermediate goal for the time being. Since I was inexperienced and had almost no knowledge this time, I reached B rank in about 2 weeks, so I will summarize what I learned. キャプチャ254.PNG


However, paiza's B rank is not particularly great. If you answer the B rank question even once, the rank will go up, so even an inexperienced person like me can get it. Just because the rank is B, it is hard to say that other problems can be solved with a margin, and I honestly don't think that the rank is reflected according to the current ability. In the first place, the training is for acquiring the basic knowledge and skills necessary for work, so the rank of Paiza is just a guide.

However, if you can solve the C rank problem and reach the B rank, it is much better than not knowing anything. In fact, by setting some goals and learning, I was able to feel the growth myself.

at least ・ You can use multiple if statements, for statements, and while statements in combination. ・ Understand the movement of operators and write code ・ You can create and operate arrays without any problems. ・ Int type and String type conversion can be performed. ・ Equals and == can be used properly ・ Simple methods such as substring and split can be used ・ You can read the desired value or character string using standard input.

I think that you can easily acquire the basics in the basics of java such as.

content of study

If you are new to full-scale programming, you may be worried whether you can do it. In fact, I was worried whether I could get B rank within the training period. However, no matter how bad you swallow, you can reach it by learning step by step.

Day 1-2 Get an overview with Progate or Dot Install

If you are not working but learning yourself, it is likely that you have already done so, but first let's get an overview of the language with Progate. What is programming? At that level, let's understand it.

It's important to note that you don't spend too much time here. As many engineers say, don't do Progate for weeks, as it doesn't make sense to try a skill check.

For Progate, java courses 1-3 are enough. It's important to get an overview, so you don't have to do the practical edition.

Day 2 Learn standard input and challenge D rank problem

After learning to some extent, you should try D rank immediately, but Paiza's problem requires the operation of "reading the value using standard input" </ b>, and if you do not understand this, you can even solve D. can not. First, let's use standard input. Java standard input explanation paiza learning [Java] If you can't master standard input, paiza's skill check will be blocked by D

I think you can understand it in half a day. Let's challenge D rank immediately after finishing.

In the skill check, the score rate is sorted in descending order, so if you are unsure about which problem to try, you can definitely choose from the top (choosing the bottom will make it more difficult).

There is nothing so difficult, so I think you can clear the D rank.

3rd-5th day Challenge D and C ranks while inputting with paiza learning

Next is C rank, but as expected, if you do a little Progate, you will be worried about your knowledge, so let's do paiza learning. There are 10 courses in total, but I think 1 to 6 are enough. Even if you could not clear the D rank at the stage of the previous day, you should be able to answer correctly if you supplement your knowledge here. When you're done, challenge C rank. If you are a complete beginner, even if you have enough knowledge, you may not be able to express it well in the program and the time will be up, but let's challenge it. I think I'm used to this area.

I solved about 40 D rank problems and then tried C rank, but I don't have to do that much. Let's go to the C rank problem immediately.

Day 6-10 Solve C rank problem and B rank level up set

In the contents of paiza, there is B rank level up set composed of D and C. If you struggle with the C rank problem, you can try this. I solved all the questions, but if I couldn't figure it out, I looked at the answer code. キャプチャ255.PNG

If you can answer about 10 C-rank questions correctly in time, proceed to the next stage.

After that ~ Challenge the B rank problem

If you do so far, I think that there is no shortage of knowledge in terms of simple B rank problems. It is necessary to think about the logic, but except for some problems, it can basically be solved by combining if and for statements. Try 5 questions and go back to C if you don't understand any of them. If you can answer correctly, you can aim for A rank and S rank, or you can go to Atcoder and train at a higher level.

Tips when you are about to be frustrated

The speed of growth is different for each person, so don't rush

Even if you have no practical experience, those who originally programmed in high school or university, or those who are appropriate may reach B rank in 2 days a day instead of 2 weeks. However, the speed of growth is different for each person, so don't rush. If you go steadily, you will definitely acquire it at the latest. If you get tired, you can take a short break.

Take care of thinking and writing for yourself

Most of the problems with paiza are basically "creating a program that works like XX". It is necessary to actually write the conditional branch here, thinking about branching under this condition with an if statement. By repeating this, the number of drawers in your head will increase, and you will be able to deal with various problems. Obviously, "time when you think and don't actually write" isn't studying, so don't do it indiscriminately (for example, taking notes in notes is meaningless).

Do not try to write neatly, give priority to whether it works as you expected

The model answers to the exercises and the code that comes out by searching on the net are neat and beautiful. However, when you are a beginner, give priority to "Can you write with the knowledge that you know the behavior you expected?" I will not be able to write it short by using a method. Even if the code is messed up, if you can manage to answer using if and for statements, it's okay now. However, if possible, it is best to have your seniors and superiors review it.

Use if you have an environment where you can listen

In my case, it was part of the company training, so I was able to ask questions to senior engineers, but I regret not having asked too many questions. If you have an environment where you can listen, use it. However, I was able to solve about 90% by examining it myself, so I think that there is no problem even if I study by myself.


I am currently studying to improve myself, but I was worried many times during the study whether I could really improve my skills. I think that I can overcome it if I work persistently, so I hope it will be helpful and encouraging for beginners who are also learning.

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