Simplex algorithm
The simplex algorithm is the foundational method for solving linear programming problems, developed by George Dantzig in 1947. It operates by traversing the vertices of the feasible polytope along its edges, moving from one vertex to an adjacent vertex with a better objective value until no further improvement is possible. Despite its exponential worst-case complexity — demonstrated by the Klee-Minty examples — the simplex method solves the vast majority of real-world linear programs with remarkable efficiency, a phenomenon that remains only partially explained by smoothed analysis and phase transition research. The algorithm's persistence across seventy years of computational history is not merely a tribute to Dantzig's ingenuity but to the fact that the simplex method is not just an optimization procedure but a geometric exploration protocol that reveals the structure of the feasible region as it searches.The simplex method is not a greedy algorithm. It is a guided walk through a polytope's skeleton, and its efficiency suggests that the skeletons of real-world optimization problems are far more structured than combinatorial geometry predicts.