Concepts4

An ordinary generating function (OGF) encodes a sequence (a_n) as a formal power series A(x) = \sum_{n \ge 0} a_n x^n.

Knapsack problems ask how to pick items under a weight (or cost) limit to maximize value or to check if a target sum is reachable.

Coin Change uses dynamic programming to find either the minimum number of coins to reach a target or the number of ways to reach it.

Dynamic programming (DP) solves complex problems by breaking them into overlapping subproblems and using their optimal substructure.