本程序中，进行加法运算的整数的长度任意，利用双向循环链表实现长整数的存储，每个节点含一个整型变量，每个节点中仅存十进制数的4位，即不超过9999的非负整数，整个链表表示为万进制数，利用头结点数据域的符号代表长整数的符号，相加过程中不破坏两个操作数链表。-The procedure, carried out integer addition operations of arbitrary length, using two-way linked list to achieve a long integer cycle storage, each node containing an integer variable, each node in the left of the decimal number 4, that is, not the more than 9999 non-negative integer, the whole list is expressed as million hexadecimal number, use the first node of the symbol data field on behalf of a long integer symbols, the sum of the process does not destroy the two operand list.