Set Duplicate Items to 0

gistfile1.cs

int[] array = {2, 3, 5, 5, 7, 11, 11, 11, 13};
int originalNumber = array[0];
for (int i = 1; i < array.Length; i++)
{
    if (array[i] == originalNumber)
    {
        array[i] = 0;
    }
    else
    {
        originalNumber = array[i];
    }
}