Fibonacci's Sequence - Memoized Java

memoized_fibonacci.java

import org.junit.Test;

import static org.junit.Assert.assertEquals;

/**
 * Created by kenny on 7/30/14.
 */
public class FibonacciTest {

    private int[] mem = new int[50];

    @Test
    public void speedTest() {
        long startTime = System.currentTimeMillis();
        fib(45);
        System.out.println("Unmemoized: " + (System.currentTimeMillis() - startTime) + "ms");

        startTime = System.currentTimeMillis();
        mfib(45);
        System.out.println("Memoized: " + (System.currentTimeMillis() - startTime) + "ms");
    }

    @Test
    public void equalValues() {
        for(int i = 0; i < 10; i++) {
            assertEquals(fib(i), mfib(i));
        }
    }

    @Test
    public void printFirst45() {
        for(int i = 0; i < 45; i++) {
            System.out.print(mfib(i) + ",");
        }
    }


    public int fib(int i) {
        if(i <= 1) { return 1; }
        return fib(i - 1) + fib(i - 2);
    }

    public int mfib(int i) {
        if(i <= 1) { return 1; }
        if(mem[i] > 0) {
            return mem[i];
        }
        mem[i] = mfib(i - 1) + mfib(i - 2);
        return mem[i];
    }

}