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/**
* Problem 16 - Power digit sum
*
* @see {@link https://projecteuler.net/problem=16}
*
* 2¹⁵ = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
*
* What is the sum of the digits of the number 2¹⁰⁰⁰ ?
*/
/**
* Returns the power digit sum of n^pow.
*
* @param {number} [n=2]
* @param {number} [pow=1000]
* @returns {number}
*/
const powerDigitSum = function (n = 2, pow = 1000) {
// The idea is to consider each digit (d*10^exp) separately, right-to-left.
// digits = [units, tens, ...]
const digits = [n]
let p = 1
while (++p 0) {
digits.push(carry % 10)
carry = Math.floor(carry / 10)
}
}
// (digits are reversed but we only want the sum so it doesn't matter)
return digits.reduce((prev, current) => prev + current, 0)
}
export { powerDigitSum }