# Category: DP Counting

## Combination & Permutation & DP Counting

Summary A majority of DP counting problems would define a rule of combination or permutation, under which, you have to calculate the total number of different combinations or permutations. Some typical rules and corresponding solutions are listed below. At most x same consecutive elements; the solution is to use a dimension to record the consecutive…

## Linear Recurrence Relation & Binary Exponentiation & DP Counting

Summary In this post, I will introduce a common technique in some DP counting problems: binary exponentiation. Typically, in these problems, you will be given a number n and you are asked to return the number of valid combinations. You need to figure out the initial state and the transform function between states. The problems…