🧮 Optimization Expert — Pyomo & OR-Tools Model Library

A hands-on, open-source library of 129+ solved optimization models in Pyomo and Google OR-Tools CP-SAT — routing, scheduling, supply chain, graphs, machine learning and puzzles.

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🚀 What Is This Repository?

A living library of optimization models. Each notebook or script is fully solved and self-contained: problem, mathematical formulation, Python code, solution and visualization.

It is written for:

• Students learning operations research and mathematical programming
• Practitioners looking for working templates for real problems
• Puzzle lovers who like to think in constraints

Modeling tools: Pyomo (LP, MILP, NLP, bilevel, DAE) and Google OR-Tools (CP-SAT and the routing library). Solvers: CP-SAT, CBC, GLPK, HiGHS, Ipopt, Gurobi and the free NEOS Server.

Most notebooks open directly in Google Colab through the badge at the top of the notebook — no installation needed.

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🗂️ Contents

• 🚛 Routing & Logistics
• 📅 Scheduling
• 🏭 Supply Chain & Resource Allocation
• 🤝 Assignment & Matching
• 🔗 Graphs & Networks
• 🧩 Logic Puzzles
• ♟️ Chess & Board Puzzles
• 💼 LinkedIn Puzzles
• 🧠 IBM Ponder This Challenges
• 📐 Geometry & Packing
• 🤖 Machine Learning & Data Fitting
• 🛠️ Pyomo & OR-Tools Techniques

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📚 Solved Problems

🚛 Routing & Logistics

Problem	File	Tool
Capacitated VRP (CVRP)	CVRP_CP.ipynb	CP-SAT
CVRP with OR-Tools routing library	CVRP_log.ipynb	OR-Tools Routing
CVRP with distance limits — comparison	Comparison_Distance_Exceed_of_CVRP_CP.ipynb	CP-SAT
CVRP with Time Windows (CVRPTW)	CVRPTW_CP.ipynb	CP-SAT
Clustered CVRP	CCVRP_CP.ipynb	CP-SAT
VRP with constraint programming	CP_VRP.ipynb	CP-SAT
TDCPVRP	TDCPVRP_V2.ipynb	CP-SAT
TSP with AddCircuit	AddCircuit_Advanced_CP.ipynb	CP-SAT
TSP with precedence constraints	precedence_AddCircuit_Advanced_CP.ipynb	CP-SAT
Large-scale TSP	Large_TSP_CP.ipynb	CP-SAT
Shortest path with waiting times	routing_shortest_path_waiting_CP_V3.ipynb	CP-SAT
VRP wiring	VRP_Circuit_CP_Wiring.ipynb	CP-SAT
VRP wiring without crossings	VRP_Circuit_CP_Wiring_nocross.ipynb	CP-SAT
Tourist trip planning (TTP)	TTP_CP.ipynb	CP-SAT
Boat tour optimization	BoatTour.ipynb	Pyomo
Order pickup from inventory	storage_routing.ipynb	CP-SAT
Conquering all metro stations	Metro map -V3-github.ipynb	Pyomo

📅 Scheduling

Problem	File	Tool
Job shop scheduling with idle time	JobShop_CP_ORTools_Idle_time.ipynb	CP-SAT
Job shop with flexible preventive maintenance (6 jobs × 5 machines)	maintenance_CP.py	CP-SAT
↳ data for the maintenance example	data_maintenance_CP.py	Python
RCPSP with cumulative constraints	RCPSP_Cummulative_CP.ipynb	CP-SAT
Multi-mode RCPSP (MRCPSP)	mrcpsp.ipynb	Pyomo
Project scheduling	Project-Class-module-github.ipynb	Pyomo
Project scheduling — multi-objective	Project-Class-module-github-MOO.ipynb	Pyomo
Shift scheduling	shift_scheduling_CP.ipynb	CP-SAT
Nurse scheduling	automation.py	CP-SAT
Hospital staff scheduling	Hospital_CP.ipynb	CP-SAT
Airline scheduling (two-stage)	Airliner-twostage.ipynb	Pyomo
Movie shooting sequence	Movie_shooting.ipynb	CP-SAT
Team meeting scheduling	TeamMeeting.ipynb	CP-SAT

🏭 Supply Chain & Resource Allocation

Problem	File	Tool
Cutting stock problem	CSP-git-V1.ipynb	Pyomo
Farmer resource allocation	Farmer_CP_V1.ipynb	CP-SAT
Bilevel optimization (single and multi follower)	bilevel-github-single-bilevel-multi-EX2.ipynb	Pyomo
Gerrymandering (district design)	Final_Gerrymandering_CP.ipynb	CP-SAT
Yield	yield.ipynb	Pyomo

🤝 Assignment & Matching

Problem	File	Tool
Stable marriage	stable_marriage_CP.ipynb	CP-SAT
Student–professor assignment	StudenttoProf.ipynb	Pyomo
Pairing	Pairing CP.ipynb	CP-SAT
Christmas gift happiness maximization	Gift-Christmas.ipynb	Pyomo
Secret Santa	Secret_Santa_Circuit_Advanced_CP.ipynb	CP-SAT
Social golfer problem	Social golfer.ipynb	Pyomo

🔗 Graphs & Networks

Problem	File	Tool
Critical node detection	CND-github.ipynb	Pyomo
Graph island detection	Graph-Island.ipynb	Pyomo
Earthquake network	earthquake.ipynb	Pyomo
Max distance on a graph	max distance.ipynb	Pyomo
Max independent set	April Fools day max independent set.ipynb	Pyomo
Vertex coloring	vertexcoloring.ipynb	Pyomo
Edge coloring	Edgecoloring.ipynb	Pyomo
Total coloring	Totalcoloring.ipynb	Pyomo
Routing & wavelength assignment	Routin_Wavelength_Assignment_CP.ipynb	CP-SAT
PCB routing	PCB.py	CP-SAT

🧩 Logic Puzzles

Problem	File	Tool
Zebra puzzle	zebra_CP.py	CP-SAT
Zebra puzzle — v2	zebra_CP_v2.py	CP-SAT
Hidato	Hidato-git.ipynb	Pyomo
Hashi (bridges)	HAshi puzzle-git.ipynb	Pyomo
Hitori	Hitori_CP.ipynb	CP-SAT
Bonairo	Bonairo puzzle .ipynb	Pyomo
Shikaku	Shikaku-puzzle-github.ipynb	Pyomo
Suguru	Suguru_CP.ipynb	CP-SAT
Numberlink	Numberlink-V3-Git.ipynb	Pyomo
Slitherlink	slitherlink_puzzle.py	CP-SAT
Slitherlink — drone variant	slitherlink_puzzle_Drone.py	CP-SAT
Slitherlink — drone variant v2	slitherlink_puzzle_Drone-V2.py	CP-SAT
Tower (Skyscraper) puzzle	tower_puzzle.py	CP-SAT
Tower puzzle — all solutions	tower_puzzle_allsolutions.py	CP-SAT
Snake	Snake_CP.ipynb	CP-SAT
Snake with eggs	snake_egg.py	CP-SAT
Snake with eggs — modular	snake_egg_modular.py	CP-SAT
Magic square	MagicSquare.ipynb	CP-SAT
Mean square	MeanSquare.ipynb	CP-SAT
ROGO	ROGO_of_AddCircuit_Advanced_CP.ipynb	CP-SAT
A puzzle a day	A_Puzzle_A_Day_git.ipynb	CP-SAT
Tiling puzzle	Tiling.py	CP-SAT
Domino placement	domino.ipynb	CP-SAT
Maze	maze.ipynb	Pyomo
Clock puzzle	Clock_CP.ipynb	CP-SAT
Calculator with two buttons	calculator_cp.py	CP-SAT
1 Euro coin	1EuroCoin.ipynb	CP-SAT
Pennies	Pennies.py	Pyomo
Empty bucket	Empty-Bucket-Github.ipynb	Pyomo
Family puzzle	Project_Family_Advanced_CP.ipynb	CP-SAT
Master Mind game	game_Master_Mind_CP_Pyomo.ipynb	CP-SAT / Pyomo
Longest common subsequence	LCS-git.ipynb	Pyomo
Maximum path sum (Project Euler 18 & 67)	maxpasssum.py	CP-SAT
Maximum path sum — visual	maxpasssum_visual.py	CP-SAT
Maximum path sum — visual, multiple paths	maxpasssum_visual_multi.py	CP-SAT
Pizza	Pizza.ipynb	CP-SAT
Easter photo	Easter Photo.ipynb	Pyomo

♟️ Chess & Board Puzzles

Problem	File	Tool
N-Queens	N-Queen.ipynb	Pyomo
Knight's tour (MILP)	Knight tour MILP.ipynb	Pyomo
One knight stands	One_Knight_Stansd_.ipynb	CP-SAT
Half chessboard	half_chess_board.ipynb	CP-SAT
Fill the chessboard	fill_chess-Github.ipynb	Pyomo
Snake on a chessboard	snake_chess_board.ipynb	CP-SAT
Board puzzle	board-git.ipynb	Pyomo
Vertex rectangle	vertex_rectangle.ipynb	CP-SAT

💼 LinkedIn Puzzles

Problem	File	Tool
Queens	Linkedin_CP_Puzzle.ipynb	CP-SAT
Queens on a multi-color board	Queen_Linkedin_of_multi_color_chess_board_CP.ipynb	CP-SAT
Tango	TANGO_of_Linkedin_CP_Puzzle.ipynb	CP-SAT
ZIP	ZIP_LInkedin_CP.ipynb	CP-SAT
Patches	patches_puzzle_CP_final.py	CP-SAT
Patches — first version	patches_puzzle_CP.py	CP-SAT

🧠 IBM Ponder This Challenges

Problem	File	Tool
Prime sequence (March 2024)	Prime_IBM_sequence_March2024.ipynb	CP-SAT
Solution callback (January 2024)	callback_CP_IBM_Ponder_this_Challenge_Jan_2024.ipynb	CP-SAT
Max army	IBM_max_Army.ipynb	CP-SAT

📐 Geometry & Packing

Problem	File	Tool
2D no-overlap placement	2d_no_overlap.ipynb	CP-SAT
Shape placement	shape_placement.ipynb	CP-SAT
Largest box	Largest_box_CP.ipynb	CP-SAT
Biggest circle with equal blue/green points	blue-green-points-biggest_circle.ipynb	Pyomo
Max points	maxpoints-V2.ipynb	Pyomo
Max distance between points	MaxDistance-Github-V2.ipynb	Pyomo

🤖 Machine Learning & Data Fitting

Problem	File	Tool
SVM — primal & dual classification	EXample_SVM_Primal_Dual_Classification_.ipynb	Pyomo
SVM — primal & dual on corn seed data	EXample_SVM_Primal_Dual_Classification_Corn_.ipynb	Pyomo
SVM — why kernels are needed	EX_final_SVM_Primal_Class_Kernel_Necessity_.ipynb	Pyomo
SVM — kernel dual, hard constraints	Class_kernel_Dual_of_SVM_hard_constraint.ipynb	Pyomo
K-means clustering	Clustering_Kmean_class.ipynb	Pyomo
K-means (class)	Kmeans_Class.ipynb	Pyomo
Multi-curve regression	regression-multiline-V4.ipynb	Pyomo
Projectile fitting from an image	projectile- GitHub-V2.ipynb	Pyomo

🛠️ Pyomo & OR-Tools Techniques

Problem	File	Tool
Pyomo on Google Colab — setup	Pyomo_on_Google_Colab.ipynb	Pyomo
Pyomo on Google Colab — example	Pyomo_example_on_Google_Colab.ipynb	Pyomo
Solving with the NEOS server	NEOS Pyomo.ipynb	Pyomo
Mutable parameters	mutable prarameter.ipynb	Pyomo
Indexed variables X[i,j] in Pyomo	Xij_Pyomo.ipynb	Pyomo
Indexed variables X[i,j] in CP-SAT	Xij_cp.ipynb	CP-SAT
Pyomo.DAE — transient heat transfer	Pyomo_dae.ipynb	Pyomo.DAE
Solving several instances in parallel (mpi4py)	multiple_instances.py	Pyomo
A simple CP model	simple_CP.py	CP-SAT
Modeling with 7 cases	7seenPyomo.ipynb	Pyomo

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⚡ Quick Start

Run locally

git clone https://github.com/OptimizationExpert/Pyomo.git
cd Pyomo

pip install pyomo ortools matplotlib pandas numpy networkx
pip install highspy            # free LP/MILP solver usable from Pyomo
conda install -c conda-forge coincbc ipopt   # optional: CBC and Ipopt

jupyter notebook

Run on Google Colab ☁️

Open any notebook with its Open in Colab badge, or start from Pyomo_on_Google_Colab.ipynb.

Pick a tool

Your problem has…	Start with
continuous variables, LP / MILP / NLP structure	Pyomo + HiGHS, CBC, Gurobi or Ipopt
sequencing, scheduling, logic, all-different, circuits	OR-Tools CP-SAT
vehicle routing with standard side constraints	OR-Tools routing library

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📡 Stay Connected

Platform	Link
🌐 Website	optexpert.org
📰 LinkedIn newsletter	Optimization in Open Source
💬 Telegram	t.me/PyomoChannel
🎓 Udemy course	Optimization in Python
👤 LinkedIn	Alireza Soroudi

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🤝 Contributing

Contributions are welcome:

1. Fork the repository and create a branch.
2. Add a notebook with a problem description, the mathematical formulation, clean code and a visualization.
3. Run it end to end.
4. Open a pull request and say which section of this README it belongs to.

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📖 How to Cite

@misc{soroudi2024pyomo,
  author       = {Alireza Soroudi},
  title        = {Optimization Expert — Pyomo \& OR-Tools Model Library},
  year         = {2024},
  publisher    = {GitHub},
  url          = {https://github.com/OptimizationExpert/Pyomo}
}

A CITATION.cff file is also included, so GitHub's "Cite this repository" button works.

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📄 License

MIT — use it, fork it, build on it.

If this library helped you, a ⭐ helps others find it.