**DADS 2nd level index page**
Up to Two-level Index

optimal
optimal cost: see best-case cost
optimal hashing: see perfect hashing
optimal merge
optimal mismatch
optimal polygon triangulation problem
optimal polyphase merge
optimal polyphase merge sort
optimal solution
optimal triangulation problem
optimal value
optimization problem
or
oracle set
oracle tape
oracle Turing machine
order
ordered array
ordered binary decision diagram: see OBDD
ordered linked list
ordered tree
order-preserving hash: see linear hash
order-preserving Huffman coding
order-preserving minimal perfect hashing
oriented acyclic graph: see directed acyclic graph