FibonacciMemo.kt

fun fibobacciMemo(n: BigInteger): BigInteger {
    var nMinus2 = BigInteger.ZERO
    var nMinus1 = BigInteger.ONE
    if (n <= BigInteger.ONE) {
        return n
    }
    var i = BigInteger.ZERO
    while (i < n) {
        i += BigInteger.ONE
        nMinus1 += nMinus2
        nMinus2 = nMinus1 - nMinus2
    }
    return nMinus2
}