This is the proceedings of the SIGAL International Symposium on Algorithms held at CSK Information Education Center, Tokyo, Japan, August 16-18, 1990. SIGAL (Special Interest Group on Algorithms) was organized within the Information Processing Society of Japan in 1988 to encourage research in the field of discrete algorithms, and held 6-8 research meetings each year. This symposium is the first international symposium organized by SIGAL. In response...