Given a list of integers nums, return a new list out of the same length where out[i] is the sum of nums[0] through nums[i] inclusive.
Examples
Input: nums = [1, 2, 3, 4]
Output: [1, 3, 6, 10]
Input: nums = [5, -5, 5]
Output: [5, 0, 5]
Constraints
0 <= len(nums) <= 10**5-10**4 <= nums[i] <= 10**4- Return a new list.
- Target: O(n) time; recomputing
sum(nums[:i+1])for each i is too slow.
Goals
- Carry an accumulator through a single pass
- Build a prefix-sum list of the same length as the input
- Handle negatives and the empty list