Crate netgen_rs 

NETGEN, a classic min-cost flow / assignment / max-flow generator.

Produces DIMACS-formatted flow problem instances (assignment, max flow, or min-cost flow) matching the original NETGEN (Klingman, Napier, Stutz, 1974) implementation, including the BCJL overflow fixes.

This crate is a pure-Rust rewrite of the reference C implementation shipped with the DIMACS network flow challenge.

Usage

Quick start

use netgen_rs::{generate, NetgenParams};

let params = NetgenParams {
    nodes: 512,
    sources: 10,
    sinks: 10,
    density: 2000,
    mincost: 5,
    maxcost: 500,
    supply: 1000,
    tsources: 3,
    tsinks: 3,
    hicost_pct: 20,
    capacitated_pct: 80,
    mincap: 50,
    maxcap: 2000,
};
let result = generate(13502460, &params).unwrap();
println!("Generated {} arcs", result.arcs.len());

Writing DIMACS output

Use write_dimacs to stream into any io::Write, or to_dimacs_string to collect into a string.

use netgen_rs::{generate, write_dimacs, NetgenParams};

let params = NetgenParams::from_slice(&[
    512, 10, 10, 2000, 5, 500, 1000, 3, 3, 20, 80, 50, 2000,
])?;
let dimacs = netgen_rs::to_dimacs_string(13502460, 1, &params)?;
println!("{}", dimacs.lines().next().unwrap());

let result = generate(13502460, &params)?;
let stdout = std::io::stdout();
write_dimacs(&mut stdout.lock(), 13502460, 1, &params, &result)?;

The 13 integers mirror the original parms[] array (see NetgenParams).

Structs

Arc

A single arc in the generated network.

NetgenParams

Parameters for network generation.

NetgenResult

Result of network generation.

Enums

NetgenError

Errors that may occur while running the generator.

ParamError

Specific parameter validation errors.

ProblemType

Problem type detected from parameters.

Functions

generate

Generate a network flow problem.

to_dimacs_string

Generate and format as DIMACS string.

write_dimacs

Write complete DIMACS output (header + network).

write_dimacs_header

Write the DIMACS-format header comments.

write_dimacs_network

Write the DIMACS-format network data (problem line, node lines, arc lines).