Dynamic Programming and Greedy: Knowing Which One Applies

Both techniques replace exponential search with something polynomial, and both fail on problems without the right structure. This path builds the recognition skill rather than a catalogue of recurrences: optimal substructure and where it breaks, choosing a state and deriving the running time from it, the exchange argument and the matroid theorem that says exactly when greedy is guaranteed, and a decision procedure to run on a problem you have never seen before.