JS Fibonacci Sequence Implementation

1. Recursion

function fib (n) {    if (n==1| | n==2) {        return 1;    }    Return Fbnq (n-1) +fbnq (n-2);} FBNQ (10);//55

2. Non-recursive

var res=[1,1];function fb (n) {for    (var i=2;i<n;i++) {        res[i] = res[i-1] + res[i-2];}    } FB (Console.log);//[1, 1, 2, 3, 5, 8, 13, 21, 34, 55]

It can be seen that the time complexity of non-recursion is O (n),

The time complexity of recursion is more complicated than that of O (2^n).

However, the non-recursive spatial complexity is less than the recursive call, and the For loop saves the corresponding values in each loop, but the recursive call does not save the corresponding values.

JS Fibonacci Sequence Implementation