JS 实现斐波那契数列 #15

function fib(n) {
    if (n == 0) {
        return 0;
    }
    if (n == 1) {
        return 1;
    }
    return fib(n - 1) + fib(n - 2);
}
console.log(fib(5));

function fib(n) {
    var a = 0,
        b = 1,
        total = 0;
    if (n < 2) {
        return n;
    }
    for (var i = 2; i <= n; i++) {
        total = a + b;
        a = b;
        b = total;
    }
    return total;
}
console.log(fib(5));