index.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]

//Solution

const runningSum = (nums) => {
    let sum = 0;
    
    return nums.reduce((acc, el) => {
        sum += el;
        acc.push(sum);
        return acc
    }, [])
};