给出以下程序的执行结果。
#include <stdio.h> struct st { int x; int * y; } * p; int s[ ]={10,20,30,40}; struct st a[ ]={1,&s[0],2,&s[1],3,&s[2],4,&s[3]}; void main() { p=a; printf("%d,",p->x); printf("%d,",( ++p)->x); printf("%d,", * ( ++p)->y); printf("%s\n", ++( * ( ++p)->y)); }