const nums = [1,2,3,4], nums2 = [1,1,1,1,1];
var runningSum1 = function(nums) {
if (!Array.isArray(nums)) return undefined;
let result = [];
let lastSum = 0;
for (let i=0; i < nums.length; i++) {
lastSum += nums[i];
result.push(lastSum);
}
return result;
};
// best solution
var runningSum3 = function(nums) {
if (!Array.isArray(nums)) return undefined;
for (let i=1; i < nums.length; i++) {
nums[i] += nums[i-1];
}
return nums;
};
const varyingSum2 = (nums) => {
if (!Array.isArray(nums)) return undefined;
return nums.reduce((acc, val) => acc + val);
}
const runningSum2 = (nums) => {
for (i = 1; i < nums.length; i++) {
nums[i] += nums[i-1];
}
return nums;
}
//console.log(runningSum2(nums));
console.log(runningSum3(nums));