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Lecture 6: Constraint Satisfaction Problems

Smart Problem Solving with Variables, Domains & Constraints

Master CSP Formulation, Backtracking, and Intelligent Heuristics
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Course Home Lecture 5: Adversarial Search Lecture 4: Local Search

From Independent to Interconnected Variables

Traditional search treats variables independently - each decision affects only the outcome.

CSP handles interconnected variables where every assignment constrains others' possibilities!

About Constraint Satisfaction Problems

Constraint Satisfaction Problems (CSPs) represent a powerful framework for solving problems involving multiple variables that must satisfy specific relationships. From scheduling classes and coloring maps to solving Sudoku puzzles, CSPs provide systematic approaches to complex combinatorial problems.

8+ Interactive Demos
4 Major Algorithms
5 Real Applications
100% Visual Learning
Duration: 2-3 hours
Topics: CSP Algorithms & Applications
Level: Intermediate

CSP Fundamentals & Theory

CSP Formulation & Modeling

Learn to model real problems as CSPs. Interactive builder for variables, domains, and constraints. See how problems transform into formal CSP representations.
Backtracking Search Algorithm

Step-by-step visualization of systematic backtracking. Watch variable assignments, conflict detection, and backtracking decisions in real-time.
Arc Consistency & Propagation

See how constraint propagation reduces domains before search. Interactive AC-3 algorithm demonstration with domain filtering visualization.
Forward Checking

Advanced constraint propagation during search. Watch real-time domain reduction and early failure detection in Map Coloring and N-Queens problems.

Intelligent Search Heuristics

Variable Ordering Heuristics

Compare MRV (Most Restricting Variable) and Degree heuristics. See how smart variable selection dramatically improves search efficiency.
Value Ordering Heuristics

Explore Least Constraining Value (LCV) strategy. Interactive comparison showing how value ordering affects search tree exploration.
Local Search for CSPs

Min-conflicts algorithm demonstration. See how local search can solve large CSPs that are challenging for systematic methods.
Advanced CSP Techniques

Forward checking, maintaining arc consistency, and hybrid approaches. Compare different CSP solving strategies side-by-side.

Hands-On Exercises & Applications

Exam Scheduling CSP - Complete Interactive Exercise

Comprehensive CSP exercise with two scenarios: impossible 2-slot scheduling vs. solvable 3-slot scheduling. Master CSP modeling, forward checking, MRV/LCV heuristics, and learn mathematical impossibility proofs using the pigeonhole principle.

Coverage: Variables & Domains • Constraint Formulation • Forward Checking • Heuristics (MRV/LCV) • Impossibility Analysis
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Saudi Arabia Map Coloring

Color Saudi regions with minimum colors while satisfying adjacency constraints. Interactive CSP formulation with real geography.

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Interactive Sudoku Solver

Build a CSP-based Sudoku solver. See how constraint propagation and backtracking solve puzzles step-by-step.

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N-Queens CSP Exercise

Model and solve the classic N-Queens problem as a CSP. Compare different heuristics and see constraint propagation in action.

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CSP Learning Path

Start with Basics

Begin with CSP formulation to understand the framework fundamentals.

Master Backtracking

Learn systematic search through the interactive backtracking demo.

Add Intelligence

Explore heuristics and constraint propagation for efficiency.

Apply Knowledge

Solve real problems through hands-on exercises and applications.

SE444: Constraint Satisfaction Problems | Interactive visualizations and real-world applications for mastering CSP algorithms