Chong Wang

September is almost over. It is time to work through LeetCode. I have long said that I would finish it, but never kept the momentum; with October approaching, I hope that three problems a day will get me through the set by year-end. While writing my diary yesterday, I realized that another notebook was nearly full. That reminded me of the many notebooks I have kept since I was seven—perhaps nearly twenty by now. Somehow, the next one feels like the second volume of my life, and I hope it will be a good one. Some competitive programmers look down on LeetCode as too easy; I disagree. Passing a problem may not be difficult, but interviews often require the best time and space complexity, which makes problems involving linked lists and STL design surprisingly demanding. I referred to many discussion threads and CSDN posts while writing these solutions.

Problem link (may require a proxy) · Code I should have worked through original written-test problems long ago, to get a sense of their difficulty and discrimination, but I kept...

Title link and Code link I saw that Div1 this time had three 2000 values (instead of 2500), and I saw Sister Cha posted [Problem Solution] (https://async.icpc-camp.org/d/555-cod...

Problem link · Code C Many Formulas Given a string of digits from 1 to 9, with length at most 10, insert + signs between digits in every possible way and compute the sum of all ...

Title link and Code link A Divide a Cuboid The meaning of the question is to give a cube of A*B*C and divide it into two parts using a face. The difference in volume of the two ...

Title link and Code link During the comparison, I only did three questions. Later, I felt that question D in this period was possible, and the idea of question E was still amazi...

School started in September, and it’s been one month so far. Let’s summarize what we have done in the past month. By the way, it’s a little embarrassing to write this when Octo...

Question link, I have never been exposed to this D question before, the overall score is two points, which is quite typical. I had a headache doing E and F. I submitted question...

I also really like this issue of Regular Contest. The questions are very interesting, question link. Code link C Tak and Cards The meaning of question C is to give N (N<=...

The last two DPs in this issue are very fun. The code is here. C Be Together The meaning of the question is to give n numbers and they must be unified into the same number. The ...