TOMS097 is a C library which computes the distance between all pairs of nodes in a directed graph with weighted edges, using Floyd's algorithm.
The computer code and data files made available on this web page are distributed under the GNU LGPL license.
TOMS097 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
CITIES, a dataset directory which contains a number of city distance datasets.
DIJKSTRA, a C program which runs a simple example of Dijkstra's minimum distance algorithm for graphs.
FLOYD, a C library which implements Floyd's algorithm for finding the shortest distance between every pair of nodes in a directed graph.
You can go up one level to the C source codes.