Description: Develop a function that takes an array of integers and its size as two parameters and does the following: For elements of the array with odd indices, the function should reverse their sign (e.g., if the element was 37, it becomes -37; if the element of the array was -5, it becomes 5). For elements with even indices, the function sets them to zero.

Example input array: arr = {1, -4, 66, 33421, 925, -8352, 7, -7, -7}

Example array after adjustment: {0, 4, 0, -33421, 0, 8352, 0, 7, 0}