Preview of the Series of Competitions of the Science and Information Technology Competition (ITC) Dear technology enthusiasts, participants, and followers, the highly anticipated series of competitions of the Science and Information Technology Competition (ITC) is about to kick off. A series of wonderful technological feasts are waiting for you! Opening Time: Every year from May to June The specific rules are as follows: The administrator of this competition is @lhj888. The competition adopts the competition systems of Leduo/OI/IOI/ACM/ICPC, and the rewards are rich. There are various types of questions. It is an advancement mode. You can contribute your own questions and get corresponding scores. There are a total of five rounds, namely the preliminary round (first round), basic round, advanced round, question contribution round, and final round. For the specific rules, please refer to the competition. There is a simulation competition available for participants to practice. More rules are currently under review. Stay tuned! Must-read before the competition: During the competition, behaviors such as using AI, plagiarizing others' code, and privately collaborating to create alt accounts are not allowed. If such behaviors are discovered, the competition results will be cancelled, and corresponding disciplinary actions will be given. Rewards: First place: Special privileges/coins/badges/special status/??? (mysterious gift) Second place: Coins/badges/special status Third place: Coins/promotion to advanced user Competition System: Adopt the Leduo competition system and the flexible time mode with a time limit of two hours. Under the Leduo competition system, participants can submit a question multiple times and get real-time evaluation results. Under the Leduo competition system, multiple submissions will lead to the deduction of participants' scores, and the leaderboard will display the highest score of the user. The ranking rule of Leduo is: Rank from high to low according to the scores calculated according to the above rules. In the flexible time mode, you can choose any start time within the opening time limit of the competition. After starting, you need to complete the competition within at most 2 hours. If the competition ends before that, you will no longer be able to answer the questions. According to different competition systems, there are different submission and ranking rules. For the OI competition system, all questions are subject to the last submission. In particular, please avoid compilation errors. The ranking rule of the OI competition system is: Those with higher total scores are ranked higher. If the total scores are equal, the rankings are the same. For the ACM/ICPC competition system, all questions are evaluated immediately after submission, and it is determined by whether they are passed or not. The ranking rule of the ACM/ICPC competition system is: Those who have passed more questions are ranked higher. If the number of passed questions is the same, those who have spent less time (including penalty time) on answering questions are ranked higher. Under the Leduo competition system, participants can submit a question multiple times and get real-time evaluation results. Under the Leduo competition system, multiple submissions will lead to the deduction of participants' scores, and the leaderboard will display the highest score of the user. The ranking rule of Leduo is: Rank from high to low according to the scores calculated according to the above rules. Under the IOI (strict) competition system, different from the IOI competition system, the leaderboard will be closed until the end of the competition. Under the IOI (strict) competition system, the score of each question on the leaderboard will be the sum of the maximum scores of each sub-task of the user in all submissions. The time and space limits are subject to the description of the questions. For the default limits, please refer to the "Limits". Limits: The HydroOJ evaluation machine calculates the time consumption using the CPU time of the process, and the time limit is the time specified by the evaluation points in the questions. The HydroOJ evaluation machine calculates the memory space consumption using the sum of the virtual memory and physical memory of the process. The default memory space limit is 256MiB. If it is specially specified in the questions, the limit is the memory space specified by the evaluation points in the questions. Input and Output: Unless otherwise specified, HydroOJ uses standard input and output (console input and output, screen input and output, STD I/O). Evaluation Status: Waiting for evaluation: The evaluation request is waiting to be fetched by the evaluation machine. Fetched for evaluation: The evaluation request has been fetched by the evaluation machine and is being prepared for evaluation. Compiling: Compiling is in progress. Judging: Compilation is successful, and evaluation is in progress. Accepted: The program output is completely correct. Wrong Answer: The program output is inconsistent with the standard answer (excluding trailing spaces at the end of lines and blank lines at the end of the file). Time Limit Exceeded: The running time of the program exceeds the limit of the question. Memory Limit Exceeded: The running memory space of the program exceeds the limit of the question. Runtime Error: There is an error during the running of the program (such as array out of bounds, division by zero, arithmetic overflow, stack overflow, invalid pointer, etc.). Compile Error: Compilation fails. System Error: There is a system error (if you encounter this problem, please feedback it in the discussion area in a timely manner). Canceled: The evaluation is cancelled. Unknown Error: There is an unknown error. Ignored: It is ignored. If there is the words "Score Cancelled", it means that the administrator has manually marked this record as cancelled, which may be due to a violation of the service terms, such as the code being found to be very similar to that of other users. Compilation Errors: The following situations may occur: Choosing the wrong programming language when submitting. The main class name in Java is not "Main". For C/C++: See below. Special reminders for C/C++ participants regarding general compilation errors: __int64 should be written as the long long type in GNU C++. The return value of main() must be defined as int, not void. The index variable i in the for statement will become invalid after a statement like "for (int i = 0...) {...}". itoa is not a universal ANSI function (this function does not exist in standard C/C++). Using the %lf format in printf is incorrect. Competition Region: Currently, there is only the AK Tianxia competition region. If you want to add a competition region or have any questions, please contact @lhj888. Q&A after the Competition: For details, please refer to the [FAQ] Q&A & Discussion Post. Others: If you have any questions during the competition, please contact @zswdlqy @lhj888. If you want to provide some questions, please contact @zswdlqy. You can open the AK Tianxia question supplement domain. You can supplement the question data. Download of Data after the Competition: Contact @zswdlqy's email for downloading the data after the competition. The rules for downloading data after the competition: Ordinary users can download 3 data points per day, and advanced users can download 5 data points per day. Providing data is prohibited in this competition. Specific Details: Regarding the competition rules of the C++ Weekly Competition and the AK Tianxia Monthly Competition. The questions will be sorted into the C++ Weekly Competition. ? Help Attention! If there is any plagiarism in the questions that infringes someone's copyright, please inform the general administrator of AK Tianxia, zswdlqy, in a timely manner, and he will deal with it immediately! Emphasis: This post cannot be deleted. It has been reviewed by @zswdlqy. You can contact him. The storage time is from April 9, 2025, to July 1, 2025.