Andy Liu obtained his doctorate in mathematics as well as a professional diploma in elementary education in 1976, qualifying him officially to teach from kindergarten to graduate school. He was an academic at his alma mater for over thirty years, where he is currently a Professor Emeritus. During that period, he ran a mathematics circle for students in upper elementary or junior high schools. The members had published over fifty papers in scientific journals.

Andy had served as the deputy leader of the USA team and the leader of the Canadian team in the International Mathematical Olympiad. He had chaired its Problem Committee once and was a member three other times. He had authored or co-authored eighteen books in mathematics, and had been credited as an editor or a co-editor for several others.

1. The Boxing Matches. 2. The First and Second Labors of Heracles. 3. The Third and Fourth Labors of Heracles. 4. The Fifth and Sixth Labors of Heracles. 5. The Seventh and Eighth Labors of Heracles. 6. The Ninth and Tenth Labors of Heracles. 7. The Loss of the Pigs. 8. The Planting of Barley. 9. The Fifteen Fruit Pies. 10. The Palace Admittance Questionnaire. 11. The Midas Touch. 12. The Collapsing Beams. 13. The Seating Plan. 14. The Forty-Nine Danaids. 15. The Quarrelsome Residents. 16. The Bears in the Caves. 17. The Phrygian Music Festival. 18. The Banquet Tickets. 19. The Eleventh and Twelfth Labors of Heracles. 20. The Summer Festival. 21. The Great Amoeba Escape. 22. The Rolling Stones. 23. The Conscientious Birds. 24. The Archipelago Tour. 25. The Fireballs and Lightningbolts. 26. The Leaded Spears. 27. The Triangular Palace. 28. The Matching of Boxes and Keys. 29. The Number-and-Coin Tricks. 30. The Unguarded Gate. 31. The Rearrangement of the Suitresses. 32. The Wily Prisoners. 33. The Selection of the Argonauts. 34. The Beef Feast. 35. The Hunters' Competitions. 36. The First Rebellion of the Giants. 37. The Second Rebellion of the Giants. 38. The Third Rebellion of the Giants. 39. The Ungrateful Refugees. 40. The Pandora Box. Appendix Source of the Problems.