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Module 4: Dynamic Programming & Optimization

Primary books: The Algorithm Design Manual and Introduction to Algorithms. Use selective reading, not full-book completion, to repair specific gaps. The authored lessons are the main path; you do not need to read all source chapters front to back.

This module develops the ability to derive a state, prove its recurrence, recover a valid output and account for resources. It includes 17 concept lessons, 10 worked examples, 20 practice problems with separate feedback, five offline labs implementing eight operations, independent assessment and a budgeted scheduling capstone. Expected focused effort is 90–125 hours, approximately 9–13 weeks at 10 hours per week; this is an author estimate awaiting learner pilots.

Scope and prerequisites​

Begin with the prerequisite diagnostic: recursion, induction, subsets, binary-search boundaries, topological order and asymptotic/bit-size reasoning from earlier modules. The diagnostic does not require prior DP mastery.

The core covers state sufficiency, counting/optimization decompositions, evaluation order, reconstruction, numeric/storage costs, sequence/capacity/grid/interval/tree states, subsets, digit bounds and greedy-versus-DP reasoning. A correct recurrence may still be exponential or pseudo-polynomial; overlap explains reuse benefits but is not a universal prerequisite for DP.

Affine alignment, Hirschberg reconstruction, profile tilings, richer optimal BSTs, advanced split optimizations and approximation methods are bounded depth options. Their names do not create extra required implementations or imply later coverage that has not been specified.

Concept map​

Lessons​

Work in order, checking the state, proof and drill on each page. A failed boundary case should be repaired before optimizing the implementation.

OrderConcept
1Optimal Substructure: When a Problem Admits DP
2Overlapping Subproblems: Why Naive Recursion Wastes Work
3Memoization vs Tabulation: Trade-offs
4Reconstructing the Solution From a DP Table
5Fibonacci and the Rolling-Array Space Reduction
6Longest Increasing Subsequence: O(n^2) and O(n log n) Patience
7Edit Distance and Sequence Alignment
8Knapsack Variants and State Design
9Grid DP: Paths, Obstacles, Collect-Maximum
10Interval DP: Matrix Chain, Optimal BST, Balloon Burst
11Tree DP: Independent Set, Diameter, Rerooting
12Bitmask DP: TSP and Subset-Enumeration DP
13Digit DP: Counting Numbers With Constraints
14State Compression and When It Is Worth It
15Proving Greedy Correctness (Exchange Argument) vs Recognizing It Fails
16DP on DAGs and Graph-Based DP
17Choosing the Right Paradigm for Optimization Problems

The additional State, Witness, and Resource Contracts page connects the lesson proofs to API design and independent verification.

Learning objectives​

By completion, independently:

  1. Distinguish histories that may be merged from those requiring more state.
  2. Derive sound, complete recurrences and disjoint cases for counting.
  3. Set empty/impossible bases and prove a valid evaluation order.
  4. Choose memoization/tabulation with a correct cache lifetime and stack bound.
  5. Reconstruct and independently validate an optimal object, accepting valid ties.
  6. Count transitions, live storage and relevant numeric bits before scaling.
  7. Prove a greedy rule or show a counterexample under a stated objective.
  8. Adapt a solved problem to a new constraint and revise the proof and resource bound.

Practice and implementation​

PathRequired work
Worked examplesTen derivations with changed-assumption checks
Foundations practiceP1–P5: states, transitions, caching, witnesses and bit costs
Sequence/grid practiceP6–P10: LIS, alignment, capacity, counting and unreachable states
Advanced clinicP11–P20: intervals, trees, subsets, digits and algorithm selection
Guided labsLIS, edit distance, knapsack, weighted intervals, matrix chain, tree independent set, TSP and digit sum
Implementation studioTargeted repair and a bounded transfer option

Keep attempts before opening practice solutions. Lab contracts require witness checks, small exhaustive oracles and source/proof review. Passing fixtures alone does not establish mastery.

Assessment and completion​

Complete the eight-task independent assessment, then use the scoring key and competency rubric. Reach level 2 in every competency; do not average away an invalid state or witness. Complete the budgeted scheduling capstone, repair gaps and take a fresh transfer task after 7–14 days.

Keep a state/proof notebook, tested implementation package, output validation, resource record and assistance disclosure. There is no arbitrary required number of mistakes or promise that content completion establishes an elite percentile.

Suggested study sequence​

BlockFocused hours
Diagnostic, 17 lessons, contracts and targeted reading30–40
Five guided implementation labs25–35
P1–P20, solution review and repair20–28
Independent assessment, remediation and delayed transfer8–12
Scheduling capstone and review7–10

Total: 90–125 hours. Depth extensions add time. Record actual effort to improve the estimate; the instructor guide separates authored, executed, independently reviewed and learner-piloted evidence.

Further support​

Mistake Clinic | Case Studies | Reading Guide | Learning Resources | Reference and Selective Reading | Instructor Guide