Lily has a chocolate bar consisting of a row of n squares where each square has an integer written on it. She wants to share it with Ron for his birthday, which falls on month m and day d. Lily wants to give Ron a piece of chocolate only if it contains m consecutive squares whose integers sum to d.
Given m, d, and the sequence of integers written on each square of Lily's chocolate bar, how many different ways can Lily break off a piece of chocolate to give to Ron?
For example, if m = 2, d = 3 and the chocolate bar contains n rows of squares with the integers [1,2,1,3,2] written on them from left to right, the following diagram shows two ways to break off a piece:
This problem comes from https://www.hackerrank.com/challenges/the-birthday-bar/problem
Author adititayal9