Symposium held in Washington, DC, January 2001. The Symposium was jointly sponsored by the SIAM Activity Group on Discrete Mathematics and by SIGACT, the ACM Special Interest Group on Algorithms and Computation Theory. Contains 130 papers, which were selected based on originality, technical contribution, and relevance. Although the papers were not formally refereed, every attempt was made to verify the main claims. It is expected that most will appear in more complete form in scientific journals. The proceedings also includes the paper presented by invited plenary speaker Ronald Graham, as well as a portion of the papers presented by invited plenary speakers Udi Manber and Christos Papadimitriou.