Ford-Fulkerson algorithm

The Ford-Fulkerson algorithm (named for L. R. Ford, Jr. and D. R. Fulkerson) computes the maximum fl

Main function is function max_flow=ff_max_flow(source,sink,capacity,nodes_number).
The graph is expressed as N by N adjacency matrix. N is the number of vertices in the graph, i.e., "nodes_number". "source","sink" are identified by the node ID. "capacity" is an N by N matrix express the edge capacity. "max_flow" is output max flow found.