#include#include#include#includestructstudent{charnum[3];//结构体charname[9];charsex;floatscore;};typedefstructLinkList{structstudentdata;structLinkList*next;}LinkList;LinkList*student1;intz=0;voidmenu(void){printf("\n学生信息管理系统\n");printf("===========\n");printf("1
添加学生信息\n");printf("2•查询学生信息\n");printf("3•修改学生信息\n");printf("4•删除学生信息\n");printf("5•输出所有学生信息\n");printf("6
查看平均成绩\n");printf("0•退出管理系统\n");printf("============\n");printf("请选择 0-6:\n");}voidAdd(LinkList*student1){LinkList*b,*r,*s;charn[12];chart;charx;intd=0,c=0;r=student1;while(r->next
=NULL)r=r->next;while(1){d=0;printf("请输入学生学号\n");getchar();scanf("%s",&n);if(strcmp(n,"0")==0)break;if(z>0){s=student1->next;t=strcmp(s->data
num,n);for(;s
=NULL;){t=strcmp(s->data
num,n);if(t==0)d++;s=s->next;}if(d
=0){printf("该学号重复\n");fflush(stdin
