LeetCode: Running Sum Of 1d Array Solution

Approach

Either mutate array by accumulate sum or calculate prefix sum

Implementation

1// approach 1: mutate the array
2var runningSum = function (nums) {
3  for (let i = 1; i < nums.length; i++) {
4    nums[i] += nums[i - 1]
5  }
6  return nums
7}
8
9// approach 2: prefix sum
10var runningSum = function (nums) {
11  const prefixSums = []
12  let sum = 0
13  for (const num of nums) {
14    sum += num
15    prefixSums.push(sum)
16  }
17  return prefixSums
18}

References

Original problem