# Solving Leetcode Interviews in Seconds with AI: Running Sum of 1d Array


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "1480" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

	# Problem Statement
	> 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 1:  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]. Example 2:  Input: nums = [1,1,1,1,1] Output: [1,2,3,4,5] Explanation: Running sum is obtained as follows: [1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+1]. Example 3:  Input: nums = [3,1,2,10,1] Output: [3,4,6,16,17]    Constraints:  1 <= nums.length <= 1000 -10^6 <= nums[i] <= 10^6  

	# Explanation
	Here's the breakdown of the solution:

*   **In-place Calculation:** The running sum is computed directly within the input array `nums` to avoid using extra space for a new array (besides the output which is technically modifying the input).
*   **Iterative Accumulation:**  We iterate through the array, adding the current element to the previous running sum, thus updating the element in place.

*   **Runtime and Space Complexity:** O(n) runtime, O(1) storage (in-place modification).

	
	# Code
	```python
	def runningSum(nums):
    """
    Calculates the running sum of an array.

    Args:
        nums: A list of integers.

    Returns:
        A list of integers representing the running sum of nums.
    """
    for i in range(1, len(nums)):
        nums[i] += nums[i-1]
    return nums
	```