【9-2】程序填空。(2)程序功能:建立学生链表,并对3个学生的成绩求和。填完完成本题。#include struct STU{int score;struct STU *next;};int main(){struct STU s[3]={{90,'\0'},{85,'\0'},{95,'\0'}};struct STU *p=s,*q;int sum;s[0].next=【1】;s[1].next=s+2;q=p->next;sum=p->score;sum+=【2】;sum+= 【3】;printf("sum=%d\n",sum);return 0;}