#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);d=0;continue;}}z++;b=(LinkList*)malloc(sizeof(LinkList));strcpy(b->data.num,n);printf("请输入学生姓名\n");scanf("%s",&b->data.name);printf("请输入学生性别(男：M 或 m；女：W 或 w)\n");scanf("%s",&x);while(x!='M'&&x!='m'&&x!='W'&&x!='w'){printf("输入有误，请重新输入性别\n");scanf("%s",&x);}b->data.sex=x;printf("请输入成绩\n");scanf("%f",&b->data.score);printf("成功添加\n");b->next=NULL;r->next=b;r=b;printf("\n 按 0 返回菜单或\n");}}voidFindOut(LinkList*student1){intj;intname=0;chari[12];LinkList*L;L=student1->next;printf("1:学号查找\n");printf("2:姓名查找\n");scanf("%d",&j);if(j==1){printf("请输入学号\n");scanf("%s",&i);for(;L!=NULL&&L->next!=NULL&&strcmp(L->data.num,i)!=0;L=L->next);if(strcmp(L->data.num,i)==0){printf("\n 学号；%s\t 姓名；%s\t 性别；%c\t绩：％f\n",L->data.num,L->data.name,L->data.sex,L->data.score);printf("\n 抱歉，并未找到学生信息\n");printf("\n 抱歉，并未找到学生信息\n");}voidAlternum(LinkList*student1){charn[12];LinkList*L;L=student1->next;printf("\n 请输入修改前的学号\n");scanf("%s",&n);for(;L!=NULL&&L->next!=NULL&&strcmp(L->data.num...
