程序填空，输出链表中的数据。#define NULL 0#includestruct student{int num,score;struct student *next;};int main(){struct student s1,s2,s3,s4,*head,*p;s1.num =1001; s1.score =90;s2.num =1002; s2.score =40;s3.num =1003; s3.score =100;s4.num =1004; s4.score =50;(1);s1.next =&s2;s2.next =&s3;s3.next =&s4;s4.next =NULL;(2);while((3)){printf("%d %d\n",p->num,p->score);(4);}}