Perf benchmark for Normal Fibonacci and Fibonacci with Memoization (Dynamic Programming)

perfbenchmarkfibonacci.js

//Fibonacci series perf comparisions
//Recursive Call vs Dynamic Programing

//1 1 2 3 5 8 13 21

//normal recursion - O(2^n)
function fibonacci1(seq) {
	if(seq === 1 || seq === 2) {
		return 1;
	} 
	return fibonacci1(seq - 1) + fibonacci1(seq - 2);
}

var t1 = performance.now();
fibonacci1(20);
var t2 = performance.now();
console.log(t2 - t1);

//Dynamic programming - caching/memoization
var arr = [1,1];
function fibonacci2(seq) {
	if(arr[seq - 1]) {
		return arr[seq - 1];
	} 
	arr[seq - 1] = fibonacci2(seq - 1) + fibonacci2(seq - 2);
	return arr[seq - 1];
}

var t1 = performance.now();
fibonacci2(20);
var t2 = performance.now();
console.log(t2 - t1);

//Dynamic programming >> Normal Recursion
//With normal recursion the browser hangs when you try to fin dout fibonacci(100)