Pythonic Way to Solve Prefix Sum

Problem

Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]).

Return the running sum of nums.

Example

Input: nums = [1,2,3,4]
Output: [1,3,6,10]
Explanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].

Pythonic Solution

Use itertools.accumulate

from itertools import accumulate

class Solution:
    def runningSum(self, nums: List[int]) -> List[int]:
        return list(accumulate(nums))

• Time Complexity: O(N)
• Space Complexity: O(1)

Result:

• Memory: Beats 94.67%
• Runtime: Beats 100%