class Solution {
public static int[] solution(int[] num_list) {
int[] result = new int[0];
if(num_list.length > 1) {
int last = num_list[num_list.length - 1];
int prev = num_list[num_list.length - 2];
if (last > prev) {
result = new int[num_list.length + 1];
System.arraycopy(num_list, 0, result, 0, num_list.length);
result[num_list.length] = last - prev;
} else {
result = new int[num_list.length + 1];
System.arraycopy(num_list, 0, result, 0, num_list.length);
result[num_list.length] = last * 2;
}
}
return result;
}
}