程序运行后的输出结果是

#include <stdio.h>
void f(int x[], int n)
{ if ( n > 1)
{ printf("%d,", x[0]);
f(&x[1], n-1);
printf("%d,", x[0]); }
else printf("%d,", x[0]);}
main( )
{ int z[3] = {4, 5, 6};
f(z, 3);
printf("\n"); }

4,5,6,5,4,