function fib(n) {

	if(n <= 2) {
		return 1;
    } else {
		return fib(n-1) + fib(n-2);
    }
}

function fibMemo(n, memo) {

 	if(memo[n]) { return memo[n]; }

	if(n <= 2) {
		return 1;
    } else {
		memo[n] = fibMemo(n-1, memo) + fibMemo(n-2, memo);
    }
	return memo[n];
}

function fibBottomUp(n, memo) {
	let f;
	for(let k = 1; k <= n+1; k++) {
        if(k <= 2) {
            f = 1;
        } else {
            f = memo[k - 1] + memo[k - 2];
        }
		memo[k] = f
    }
	return memo[n];
}

function time(f, ...a) {

	return new Promise(
		(ok, nok) => {
            ok(f(...a));
    	}
	);

}

(async () => {
	let start = new Date().getTime();
	console.log('Computing value with Fibo Recursive Naive ...');
	console.log(await time(fib, 44));
	console.log('OK in ' + (new Date().getTime() - start)/1000 + 's');

	start = new Date().getTime();
    console.log('Computing value with Fibo DP Memoizing ...');
	console.log(await time(fibMemo, 44, []));
	console.log('OK in ' + (new Date().getTime() - start)/1000 + 's');

	start = new Date().getTime();
    console.log('Computing value With Fibo DP Bottom Up ...');
	console.log(await time(fibBottomUp, 44, []));
	console.log('OK in ' + (new Date().getTime() - start)/1000 + 's');
})();