Automation of students’ program codes verification is an important task, as it provides an opportunity to provide prompt and effective feedback to the student, significantly reduce resource costs for checking solutions. In connection with the rapid development of AI systems, new opportunities and approaches of its automation appear. We consider a fundamentally new approach for estimation of time complexity of an algorithm. The study used AI systems for estimation the complexity of the algorithm based on code fragments. According to the obtained results, a decision is made regarding the suitability of these systems for automating the evaluation of students’ program codes. We also offer for consideration the methods of implementing such approaches to the automation of checking student assignments in IT-related subjects based on AI systems. To assess the time complexity of code fragments, we used Chat GPT, Bard, TimeComplexity.ai, Chatsonic. All AI systems which participated in the experiment accurately determined the algorithmic complexity for each of the code fragments written in Python. The results indicate that ChatGPT and Google Bard demonstrated satisfactory accuracy assessing time complexity of code fragments written in Java. We developed an API which allows to partially automate teacher’s work during checks of students’ assignments