JavaScript:实现Factorial digit sum阶乘数字和算法
/**
*
* n! means n × (n − 1) × ... × 3 × 2 × 1
*
* For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
* and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27
*
* Find the sum of the digits in the number 100!
*/
const factorialDigitSum = (n = 100) =>