Straight-line programs with one input variable. Oscar H. Ibarra and Brian S. Leininger . The complexity of the equivalence problem for simple loop-free programs. A fast algorithm for the Euclidean traveling salesman problem, optimal with probability one.
Dynamic programming is optimal for nonserial optimization problems.
On the expected performance of scanning disks. Robert P. Burton and David R. Smith . A hidden-line algorithm for hyperspace. John H. Reif and Robert E. Tarjan . Symbolic program analysis in almost-linear time.