public class DoubleEven {
    static int[] doubleEven(int[] array) {
        // Figure out the size of the result array
        int num = 0;
        for(int i=0;i<array.length;i++) {
            if(array[i] % 2 == 0) num++;
            num++;
        }
        // Allocate the result array
        int[] result = new int[num];
        int n = 0;
        // Copy values into the array
        for(int i=0;i<array.length;i++) {
            if(array[i] %2 == 0) result[n++] = array[i];
            result[n++] = array[i];
        }
        return result; // return the result
    }
    public static void main(String[] args) {
        for(int n : doubleEven(new int[]{1,2,3,4,7,8,9,10,88,89,91}))
            System.out.println(n); } }