Cumulative Sum

Compute the cumulative sum (also known as prefix sum or scan) of an input array:

$$\text{output}[i] = \sum_{j=0}^{i} \text{input}[j]$$

The cumulative sum at each position is the sum of all elements up to and including that position.

Input:

• Vector $\text{input}$ of size $\text{N}$

Output:

• Vector $\text{output}$ of size $\text{N}$ containing cumulative sums

Notes:

• The first element of the output is equal to the first element of the input
• This problem is adapted from KernelBench