🤖 Artificial Intelligence Week 1 of 14 BSc · Y2 ⏱ ~50 min

Week 1: Uninformed Search, Heuristics & A*

Implement and analyze AI search algorithms: BFS, DFS, A*, minimax with alpha-beta pruning, and constraint satisfaction — the classic AI problem-solving toolkit.

University of Aliens

AI201 — Lecture 1 · BSc Y2

🎬 CC Licensed Lecture

0:00 / —:—— 📺 MIT OpenCourseWare (CC BY-NC-SA)

🎯 Learning Objectives

Implement BFS, DFS, UCS, and A* search algorithms
Prove A* optimality given an admissible heuristic
Apply minimax with alpha-beta pruning to two-player games
Model and solve constraint satisfaction problems

Topics Covered This Lecture

Uninformed Search: BFS, DFS, UCS

Informed Search: Greedy, A*, Beam

Adversarial Search: Minimax & Alpha-Beta

Constraint Satisfaction: Arc Consistency

📖 Lecture Overview

This first lecture establishes the foundational framework for Search Algorithms & Problem Solving. By the end of this session, you will have the conceptual grounding and practical starting point needed for the rest of the course.

        Why this matters
        Implement and analyze AI search algorithms: BFS, DFS, A*, minimax with alpha-beta pruning, and constraint satisfaction — the classic AI problem-solving toolkit. This lecture sets up everything that follows — make sure you understand the core concepts before proceeding to Week 2.
      

Key Concepts

The lecture introduces the four main pillars of this course: Uninformed Search: BFS, DFS, UCS, Informed Search: Greedy, A*, Beam, Adversarial Search: Minimax & Alpha-Beta, Constraint Satisfaction: Arc Consistency. Each will be explored in depth over the 14-week curriculum, with hands-on projects reinforcing theory at every stage.

# Quick Start: verify your environment is ready for AI201
import sys
print(f"Python {sys.version}")

# Check key libraries are installed
try:
    import numpy, pandas, matplotlib
    print("✅ Core libraries ready")
except ImportError as e:
    print(f"❌ Missing: {e} — run: pip install numpy pandas matplotlib")

This Week's Focus

Focus on mastering: Uninformed Search: BFS, DFS, UCS and Informed Search: Greedy, A*, Beam. These are the prerequisites for everything in Week 2. The concepts build on each other — do not skip the practice exercises.

📋 Project 1 of 3 50% of Final Grade

AI201 Project 1: 15-Puzzle Solver with A*

Implement an A* solver for the 15-puzzle (sliding tile). Design and compare 3 admissible heuristics. Measure nodes expanded, time to solution, and solution quality.

A* implementation with pluggable heuristics
3 admissible heuristics (Manhattan, misplaced, pattern DB)
Benchmark: nodes expanded vs heuristic quality
Interactive visualizer of search progress

50%

3 Projects

20%

Midterm Exam

30%

Final Exam

📝 Sample Exam Questions

These represent the style and difficulty of questions you'll see on the midterm and final. Start thinking about them now.

Conceptual Short Answer

Prove that A* is optimal if the heuristic is admissible and consistent. Sketch the proof.

Analysis Short Answer

What is alpha-beta pruning? How does it improve minimax without changing the result?

Applied Code / Proof

Define arc consistency (AC-3). How does it reduce the search space in a CSP?