Hands-On Data Structures and Algorithms with JavaScript

Memoized Fibonacci generator

We can further enhance the generator using memoization, which is a technique of calculating a value only once and remembering it for later:

function memoizedFibonacci(num) {   if (num == 0) {      memory[num] = 0;      return 0;   } else if (num == 1 || num == 2) {      memory[num] = 1;      return 1;   } else {      if (!memory[num]) {         memory[num] = memoizedFibonacci(num - 1) +         memoizedFibonacci(num - 2);      }      return memory[num];   }}

Here, we are relying on an in-memory variable called memory to store and retrieve the previously calculated value of the Fibonacci number within the series, hence avoiding a series of duplicate calculations.

If you log the time taken for each of these methods, you can see that as the size of the input number increases, ...