aershov24

public int fibonacci(int n)  {
    if (n < 2) return n;

    return fibonacci(n - 1) + fibonacci(n - 2);
}

aershov24

function fib(n, a = 0, b = 1){
  if (n > 0) {
    return fib(n - 1, b, a + b)
  }
  return a
}

aershov24

def F():
    a,b = 0,1
    while True:
        yield a
        a, b = b, a + b

aershov24

3/2 = 1.5
5/3 = 1.666666666...
...
233/377 = 1.618055556...

aershov24

function fib(n) {
  if (n < 2){
    return n
  }
  return fib(n - 1) + fib (n - 2)
}

aershov24

from math import *

phi = 1.61803399
sqrt5 = sqrt(5)

def F(n):
    return int((phi**n - (1-phi)**n) /sqrt5)

def isFibonacci(z):
    return F(int(floor(log(sqrt5*z,phi)+0.5))) == z

aershov24

private static final int FIB_0 = 0;
private static final int FIB_1 = 1;

private int calcFibonacci(final int target) {
    if (target == 0) { return FIB_0; }
    if (target == 1) { return FIB_1; }

    return calcFibonacci(target, 1, FIB_1, FIB_0);
}

aershov24

public static void BinaryTreeToDLL(Node root) {
    if (root == null)
        return;
    BinaryTreeToDLL(root.left);
    if (prev == null) { // first node in list
        head = root;
    } else {
        prev.right = root;
        root.left = prev;
    }

aershov24

static int fibMemo[];

public static int fibByRecMemo(int num) {

    if (num == 0) {
        fibMemo[0] = 0;
        return 0;
    }

    if (num == 1 || num == 2) {

aershov24

function fib(n){
  if (n === 1) return 0;
  if (n === 2) return 1; 
  return fib(n — 1) + fib(n — 2);
}