Count of positives / sum of negatives

Count of positives / sum of negativesCodewars

Approach

1. if input is not array return empty array

2. fold(reduce) inputs with initialize value [0, 0]

   1. while fold if current value is positive add '1' in first elements of init value

   2. while fold if current value is negative value add in second elements of init value

   3. pass accumulate value to next fold

3. return process-2 result

time-complexity (Big-O) is O(n)

Solution

JavaScript

const countPositivesSumNegatives = (input) => input && input.length ? input.reduce((acc, cur) => {
  if (cur > 0) {
    acc[0] += 1;
  } else {
    acc[1] += cur;
  }
  return acc;
}, [0, 0]) : [];