determine complexity class [closed]

Question

What is the big o notation here? An explanation would be appreciated. Thanks.

public static int[] mystery1(int[] list) {

  int[] result = new int[2 * list.length];
  for (int i = 0; i < list.length; i++) {
    result[2 * i] = list[i] / 2 + list[i] % 2;
    result[2 * i + 1] = list[i] / 2;
  }

  return result;

}

Answer 1

It is O(n), where n is the length of the list. You go through the entire list once in any case.

The number of arithmetic operations are:

• 2n multiplications
• 2n additions
• 2n divitions
• n modulo operations

This is not counting the arithmetic operations for implementing the for loop.