private ArraySet UnionAndIntersResult(String posfix)
{
Stack <ArraySet> stack = new Stack <ArraySet>();
foreach (char c in posfix.ToCharArray())
{
if (c == 'U' || c == 'u')
{
ArraySet resultTemp = stack.Pop().Union(stack.Pop());
stack.Push(resultTemp);
}
else if (c == 'n')
{
ArraySet resultTemp = stack.Pop().intersection(stack.Pop());
stack.Push(resultTemp);
}
else if (c == '-')
{
ArraySet resultTempB = stack.Pop();
ArraySet resultTempA = stack.Pop();
stack.Push(resultTempA.difference(resultTempB));
}
else
{
ArraySet temp1 = setList[getIndexFromChar(c)];
stack.Push(temp1);
}
}
return(stack.Pop());
}