修改程序C6_11.cpp，使它输出国际日期格式，即：使用月份的前三个字母表示月，用两个字符表示年。例如，把日期March 18, 1983表示为：

18 Mar 83-Modify the program C6_11.cpp, make it output the international date format, ie: use the first three letters of the month is the month, with two characters that year. For example, the date of March 18, 1983 is expressed as: 18 Mar 83