<p>AtCoder Beginner Contest (ABC) is a weekly online competitive programming contest run on AtCoder, Japan's largest competitive programming platform. Each round presents seven algorithmic tasks of increasing difficulty over 100 minutes, rated for participants with rating up to 1999.</p> <ul> <li>Open to all ages globally; free AtCoder account required; Singapore students participate fully</li> <li>Typically held Saturday evenings Japan time (late evening Singapore time)</li> <li>100-minute contest window with seven problems labelled A through G</li> <li>Rated range 0–1999; participants above 1999 compete unrated</li> <li>Problem point values range from 100 (Problem A) up to around 600 (Problem G)</li> <li>AtCoder also runs Regular Contest (ARC) and Grand Contest (AGC) for more advanced participants</li> </ul> <p>Register a free AtCoder account and join upcoming ABC rounds from the Present Contests page.</p>