Problem Statement

Given a one-dimensional array of integers, create a new array that represents the running sum of the original array.

The running sum at position i in the new array is calculated as the sum of all the numbers in the original array from the 0th index up to the i-th index (inclusive). Formally, the resulting array should be computed as follows: result[i] = sum(nums[0] + nums[1] + ... + nums[i]) for each i from 0 to the length of the array minus one.

Examples

Example 1

• Input: [2, 3, 5, 1, 6]
• Expected Output: [2, 5, 10, 11, 17]
• Justification:
  • For i=0: 2
  • For i=1: 2 + 3 = 5
  • For i=2: 2 + 3 + 5 = 10
  • For i=3: 2 + 3 + 5 + 1 = 11
  • For i=4: 2 + 3 + 5 + 1 + 6 = 17

Example 2

• Input: [1, 1, 1, 1, 1]
• Expected Output: [1, 2, 3, 4, 5]
• Justification: Each element is simply the sum of all preceding elements plus the current element.

Example 3

• Input: [-1, 2, -3, 4, -5]
• Expected Output: [-1, 1, -2, 2, -3]
• Justification: Negative numbers are also summed up in the same manner as positive ones.

Constraints:

• 1 <= nums.length <= 1000
• -10^6 <= nums[i] <= 10^6

Try it yourself

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