# Background Imagine, you have a big array `A`, which is mostly zeroes, but contains a short subarray `B` which has only strictly positive entries. For instance: | B | [0 0 0 0 1 2 3 0] | A | Now say, we split the array `B` into consecutive subarrays of length `d` (with a shorter final array, if the `d` doesn't divide the length of `B`). For `d = 3`: [0 0 0 0 1 2 3 0] | | [0 0 0] [0 1 2] [3 0] And now sum up each of those arrays: [0 3 3] And discard zero sums: [3 3] # The Challenge You're to write a function which prints that final array of sums in any convenient array format, given the following 5 parameters (or any subset thereof, if you don't need all of them): - The small array `B`. - The size of the small array `B` (`3` in the above example). - The *size* of the big array `A` (`8` in the above example). - The index where the small array begins (`4` in the above example). - The length `d` of the subarrays (`3` in the above example). # The Rules - You are not allowed to construct the big array `A` explicitly! - You are not allowed to construct any of the subarrays of length `d` explicitly! - That means you have to get the computation directly from the `B` and the other parameters at your disposal! Fewest characters wins!