The fourth edition of the Competitive Programming series (CP4) is widely regarded as an essential reference for individuals interested in programming contests. Developing strong command over the topics covered in this volume can significantly improve one’s problem-solving abilities and competitive coding skills, although true mastery also requires consistent practice beyond the book itself. Readers who may benefit from Book 1 alone include: High school or secondary-level students preparing for programming competitions such as national or international informatics olympiads, since this volume aligns closely with common olympiad syllabi. University students seeking additional resources to strengthen their understanding of fundamental data structures and algorithmic concepts. Individuals preparing for technical interviews that emphasize core algorithmic knowledge and problem-solving techniques. Readers who may benefit from studying both Book 1 and Book 2 include: University competitors participating in collegiate programming contests, as the second volume introduces a broader range of advanced computer science topics frequently seen in such events. Educators, trainers, and mentors searching for structured and extensive teaching material. Programming enthusiasts who enjoy tackling algorithmic challenges through coding and participating in various global contests and online competitions.