fibonacci_array.java

package com.veinhorn.playground;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) throws IOException {
        int[] numbers = fibonacci(47);

        String test = "test";
    }

    public static int[] fibonacci(int size) {
        if (size < 0) {
            throw new IllegalArgumentException("Illegal n value");
        } else if (size == 0) {
            return new int[] {};
        } else if (size == 1) {
            return new int[] { 0 };
        }

        int[] data = {0, 1, size};
        int numbers[] = new int[size];

        while (data[2] > 0) {
            if (data[2] == size) {
                for (int i = 0; i < data.length - 1; i++) numbers[i] = data[i];
                data[2] -= 2;
            } else {
                int sum = data[0] + data[1];
                data[0] = data[1];
                data[1] = sum;
                numbers[size - data[2]] = sum;

                data[2]--;
            }
        }

        return numbers;
    }
}