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].
var runningSum = function(nums) {
const array = new Array (nums.length);
array[0] = nums[0];
for( let i=1; i<nums.length; i++){
array[i] = nums[i] + array[i-1]
}
};
the result turns out to be undefine, I don't know where I did wrong.
You have to return the array
so
var runningSum = function(nums) {
const array = new Array (nums.length);
array[0] = nums[0];
for( let i=1; i<nums.length; i++){
array[i] = nums[i] + array[i-1]
}
return array;
};
instead of
var runningSum = function(nums) {
const array = new Array (nums.length);
array[0] = nums[0];
for( let i=1; i<nums.length; i++){
array[i] = nums[i] + array[i-1]
}
};
Here is another approach to solve the problem using recursion.
const nums = [1, 2, 3, 4];
const runningSum = (arr, result = [], sum = 0) => {
if (arr.length === 0) return result;
const tmp = sum + arr.shift();
result.push(tmp);
return runningSum(arr, result, tmp);
};
console.log(runningSum(nums));
return array