1480. Running Sum of 1d Array.js

// 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

const runningSum = nums => {
	let ans = new Array(nums.length)
	ans[0] = nums[0]
	for (let i = 1; i < nums.length; i++) {
		ans[i] = ans[i - 1] + nums[i]
	}
	return ans
}