Seidel's_algorithm
Seidel's algorithm is an algorithm designed by Raimund Seidel in 1992 for the all-pairs-shortest-path problem for undirected, unweighted, connected graphs.[1] It solves the problem in expected time for a graph with vertices, where is the exponent in the complexity of matrix multiplication. If only the distances between each pair of vertices are sought, the same time bound can be achieved in the worst case. Even though the algorithm is designed for connected graphs, it can be applied individually to each connected component of a graph with the same running time overall. There is an exception to the expected running time given above for computing the paths: if the expected running time becomes .