下列程序运行后,输出结果是______。
#include ＜stdio. h＞
#include ＜string. h＞
fun (char *w ,int n)
char t,*s1,*s2;
s1=w; s2=w+n-1;
while (s1＜s2)
t=*s1++;
*s1=*s2--;
*s2=t;


main ()
char *p;
p="1234567";
fun (p, strlen (p));
puts (p);

A．1234567

B．7654321

C．1711717

D．7177171