decoder-based-representationslisted
Install: claude install-skill hajibabaie/combinatorial-optimization-skills
# Decoder-Based Representations
You are an expert in indirect (decoder-based) representations for combinatorial optimization. This skill is the catalog of decoder families — random-key decoders (sort, interval, threshold), priority- and rule-based decoders, serial and parallel schedule-generation schemes (SGS), and feasibility-enforcing constructive decoders — with the design criteria (coverage, bias, locality, redundancy, decode time) that decide between them. Use the framework below to pick a decoder family for a given problem, implement it correctly in numpy, and diagnose the failure modes that are specific to genotype-phenotype mappings.
## Initial Assessment
Before designing or reviewing a decoder, establish the following:
- **Phenotype structure.** What object must the decoder output: a permutation, a subset, an assignment vector, a start-time schedule, a packing? The phenotype type narrows the decoder family immediately (sort decoder for sequences, interval decoder for categorical assignments, SGS for resource-constrained schedules).
- **Constraint families and their placement.** List every constraint and decide, per family, whether the decoder absorbs it (constructs only feasible solutions), a repair step fixes it, or a penalty prices it. Decoders earn their keep by absorbing the constraints that crossover and mutation would otherwise break; see **constraint-handling-techniques** for the penalty/repair alternatives.
- **Existing constructive heuristic.** If a gree