Return the nth number in the Fibonacci Sequence

Fib.java

import java.util.Map;
import java.util.HashMap;

class Fib {
	static long getFibIterative(int n) {
		if(n < 2) 
			return n;
		long a = 0, b = 1, c = a + b;
		for(int i = 2; i <= n; c = a+b, a = b, b = c, i++);
		return c;
	}

	static long getFibRecursive(int n) {
		return n < 2 ? n : getFibRecursive(n-1) + getFibRecursive(n-2);
	}

	static Map<Integer, Long> map = new HashMap<>();
	static long getFibRecursiveEnhanced(int n) {
		if(n < 2)
			return n;

		Long value = map.get(n);
		if(value == null){
			long ans = getFibRecursiveEnhanced(n-1) + getFibRecursiveEnhanced(n-2);
			map.put(n, ans);
			value = ans;
		}
		return value;
	}

	public static void main(String[] args) {
		int n = Integer.parseInt(args[0]);
		for(int i = 0; i < n; i++)
			System.out.print(getFibIterative(i) + " ");

		// System.out.println();
		// for(int i = 0; i < n; i++)
		// 	System.out.print(getFibRecursive(i) + " ");

		System.out.println();
		for(int i = 0; i < n; i++)
			System.out.print(getFibRecursiveEnhanced(i) + " ");
	}
}