fibonacci

fibonacci.js

function fibonacci (n) {
	return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
};

var fibonacci_memo = (function () {
	var memo = [0,1];
	function fib (n) {
		var result = memo[n];
		if (typeof result !== 'number') {
			result = fib(n - 1) + fib(n - 2);
			memo[n] = result;
		}
		return result;
	};
	return fib;
}());

for (var i = 0; i <= 40; i += 1) {
	console.log('// ' + i + ': ' + fibonacci(i));
}

for (var i = 0; i <= 40; i += 1) {
	console.log('// ' + i + ': ' + fibonacci_memo(i));
}