LeetCode: Count Integers With Even Digit Sum Solution

Approach

Populate new array with digit sum

Filter even elements

Implementation

1var countEven = function (num) {
2  const digitSum = num =>
3    num
4      .toString()
5      .split("")
6      .map(Number)
7      .reduce((acc, el) => acc + el, 0)
8
9  const isEven = num => num % 2 === 0
10
11  return Array.from({ length: num }, (_, i) => i + 1)
12    .map(digitSum)
13    .filter(isEven).length
14}

References

Original problem

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