Dynamic Programming in JavaScript

Dynamic programming breaks down the problem into smaller and yet smaller possible sub-problems. These sub-problems are not solved independently. Rather, results of these smaller sub-problems are remembered and used for similar or overlapping sub-problems.

Dynamic programming is used where we have problems, which can be divided into similar sub-problems so that their results can be re-used. Mostly, these algorithms are used for optimization. Before solving the in-hand sub-problem, the dynamic algorithm will try to examine the results of the previously solved sub-problems. The solutions of sub-problems are combined in order to achieve the best solution.

For a problem to be using dynamic programming,

• The problem should be able to be divided into smaller overlapping sub-problem.
• An optimum solution can be achieved by using an optimum solution of smaller sub-problems.
• Dynamic algorithms use memorization.

Dynamic programming problems can be solved using 2 approaches −

• Bottom Up Dynamic programming: In this approach, we first analyze the problem and see the order in which the sub-problems are solved.We start by solving the trivial sub problem and build up towards the given problem.

• Top Down Dynamic Programming: In this approach, we start solving the given problem by breaking it down. If you see that a given sub problem has been solved already, then just return the stored solution.