Make the array even

You are given an array A of N integers. If you make the array whole using the following operation, then what is the minimum number of operations required to make the entire array even?

Note: It can be proved that this is always possible.

Operation

Select an index  $1\le i<N$  and perform operation:

P=Ai+Ai+1; Q=Ai-Ai+1;

Ai=P; Ai+1=Q;

Example:

Input:  n=4, a[]={1,3,2,2}
Output: 1

Approach

Java

public class MakeArrayEven {
    public static void main(String[] args) {
        int n = 4;
        int[] a = { 1, 3, 2, 2 };
        int ans = 0;
        for (int i = 0; i < n; i++) {
            // if even
            if (a[i] % 2 == 0)
                continue;

            if (i == n - 1) {
                ans += 2;
                continue;
            }

            // if even
            if (a[i + 1] % 2 == 0) {
                ans += 2;
                a[i + 1] = 2 * a[i + 1];
            } else {
                ans += 1;
                a[i + 1] = a[i] - a[i + 1];
            }
        }
        System.out.println(ans);
    }
}