Print out the n-th entry in the fibonacci series. The fibonacci series is an ordering of numbers where each number is the sum of the preceeding two. For example, the sequence [0, 1, 1, 2, 3, 5, 8, 13, 21, 34] forms the first ten entries of the fibonacci series. Example: fib(4) === 3

fib.js

// Memoize to make more performant
function memoize(func) {
  const cache = {};
  return function(...args) {
    if (cache[args]) return cache[args];
    const result = func.apply(this, args);
    cache[args] = result;
    return result;
  };
}

// Recursive solution
function fib(n) {
  if (n < 2) return n;
  return fib(n - 1) + fib(n - 2);
}

fib = memoize(fib);

// Iterative solution
// function fib(n) {
//   const results = [0, 1];

//   for (let i = 2; i <= n; i++) {
//     results.push(results[i - 1] + results[i - 2]);
//   }

//   return results[n];
// }