表达式必须具有算术或未区分范围的枚举类型

S.base = (SElemType*)malloc(STACK_INIT_SIZE) * sizeof(SElemType);

少了一对括号，改为：

S.base = (SElemType*)malloc((STACK_INIT_SIZE) * sizeof(SElemType));

newbase = (ElemType * )realloc(L.elem, L.listsize + LISTCREMENT) * sizeof(ElemType);