DAY34：Product of consecutive Fib numbers

題目連結

https://www.codewars.com/kata/5541f58a944b85ce6d00006a

解法

第一版

function productFib(prod) {
    let fn = [0, 1]
    for (let i = 0; i < prod; i++) {
        fn.push(fn[i] + fn[i + 1])

        if (fn[i] * fn[i + 1] === prod) {
            return [fn[i], fn[i + 1], true]
        } else {
            if (fn[i] * fn[i + 1] < prod && fn[i + 1] * fn[i + 2] > prod) {
                return [fn[i + 1], fn[i + 2], false]
            }
        }
    }
}

第二版：簡化

function productFib(prod) {
    let [a, b] = [0, 1];
    while (a * b < prod) {
        [a, b] = [b, a + b];
    }
    return [a, b, a * b === prod];
}