#include<iostream.h>#include<string.h>#include<fstream.h>#include <stdlib.h>#include <time.h>//using namespace std;const int count =3;class situaction;class student{ public:int sno;char sname[20];char sex[3];int age;char depart[20];char classno[20];char lianx[40];//public:friend void sselect();friend void supdate();friend void sdelet();friend void saccount();friend void sdisplay();friend istream & operator >> (istream & in,student &stu){in>>stu.sno>>stu.sname>>stu.sex>>stu.age>>stu.depart>>stu.classno>>stu.lianx;return in;}friend ostream & operator<< ( ostream & out,student &stu){out<<stu.sno<<" "<<stu.sname<<" "<<stu.sex<<" "<<stu.age<<" "<<stu.depart<<" "<<stu.classno<<" "<<stu.lianx<<endl;return out;}friend void xkadd();friend void sadd();};void sadd(){ while(1){int flag1=0;student s;cout<<"请输入要添加的学生的学号、姓名、性别、年龄、系别、班级、联系式"<<endl;cin>>s;ifstream in("e:\\studentfile.txt");if(!in){cout<<"打开学生信息文件失败！"<<endl;return ;}student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(s.sno==stu.sno) {flag1=1; break;}in.read((char*)&stu,sizeof(student));}in.close();if(flag1==1) cout<<"该学生已经在文件中存在不允添加！" <<endl;else{ ofstream out("e:\\studentfile.txt",ios::app);out.write((char*)&s,sizeof(student));out.close();}system("pause");break;}}void sselect(){ while(1){ system("cls");cout<<"***********请选择要查询的类别：*************"<<endl;cout<<"*********** 按学生学号请按1：************* "<<endl;cout<<"*********** 按学生姓名请按2：*************"<<endl;cout<<"*********** 按学生系别请按3：*************"<<endl;cout<<"*********** 按学生班级请按4：*************"<<endl;cout<<"*********** 返回上一级界面请按5：*************"<<endl;int sn;cin>>sn;while(sn>5||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;ifstream in("e:\\studentfile.txt");if(!in){ cout<<"打开学生信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的学生的学号"<<endl;cin>>no;student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(no==stu.sno) {cout<<stu<<endl; flag=1;}in.read((char*)&stu,sizeof(student));}break;}case 2: {char name[20];cout<<"请输入要查询的学生的姓名"<<endl;cin>>name;student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(strcpy(name,stu.sname)==0) {cout<<stu<<endl; flag=1;}in.read((char*)&stu,sizeof(student));}break;}case 3: {char dep[20];cout<<"请输入要查询的学生的系别"<<endl;cin>>dep;student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(strcmp(dep,stu.depart)==0) {cout<<stu<<endl; flag=1;}in.read((char*)&stu,sizeof(student));}break;}case 4: {char clno[20];cout<<"请输入要查询的学生的班级"<<endl;cin>>clno;student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(strcmp(clno,stu.classno)==0) {cout<<stu<<endl; flag=1;}in.read((char*)&stu,sizeof(student));}break;}case 5: return ;}in.close();if(flag==0) cout<<"要查询的学生在文件不存在！" <<endl;system("pause");}}void supdate(){ while(1){ system("cls");cout<<"***********请选择按下列类别查询后修改：*************"<<endl;cout<<"*********** 按学生学号请按1：************* "<<endl;cout<<"*********** 按学生姓名请按2：*************"<<endl;cout<<"*********** 按学生系别请按3：*************"<<endl;cout<<"*********** 按学生班级请按4：*************"<<endl;cout<<"*********** 返回上一级界面请按5：*************"<<endl;int sn;cin>>sn;while(sn>5||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;fstream in("e:\\studentfile.txt",ios::in|ios::out);if(!in){ cout<<"打开学生信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的学生的学号"<<endl;cin>>no;student stu;int i=0;in.seekg(i*sizeof(student),ios::beg);in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(no==stu.sno){ cout<<stu<<endl;cout<<"请输入要修改的学生的学号、姓名、性别、年龄、系别、班级、联系式"<<endl;cin>>stu;in.seekp(i*sizeof(student),ios::beg);in.write((char*)&stu,sizeof(student));flag=1;}i++;in.seekg(i*sizeof(student),ios::beg);in.read((char*)&stu,sizeof(student));}break;}case 2:case 3:case 4:case 5: return ;}in.close();if(flag==0) cout<<"要修改的学生在文件不存在！" <<endl;system("pause");}}void sdelet(){ while(1){ system("cls");cout<<"***********请选择按下列类别查询后删除：*************"<<endl;cout<<"*********** 按学生学号请按1：************* "<<endl;cout<<"*********** 按学生姓名请按2：*************"<<endl;cout<<"*********** 按学生系别请按3：*************"<<endl;cout<<"*********** 按学生班级请按4：*************"<<endl;cout<<"*********** 返回上一级界面请按5：*************"<<endl;int sn;cin>>sn;while(sn>5||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;student stu[20];int flag=0;switch(sn){case 1: { ifstream in("e:\\studentfile.txt");if(!in){ cout<<"打开学生信息文件失败！"<<endl;return ;}int n=0;in.read((char*)&stu[n],sizeof(student));while(!in.eof()){ n++;in.read((char*)&stu[n],sizeof(student));}in.close();int no;cout<<"请输入要删除的学生的学号"<<endl;cin>>no;for(int i=0;i<n;i++){ if(no==stu[i].sno){ cout<<stu[i]<<endl;cout<<"是否要删除该学生的信息！"<<endl;char ch;cin>>ch;if( ch='Y'||ch=='y'){for(int j=i;j<n;j++)stu[j]=stu[j+1];n--;}flag=1;}}if(flag==0) cout<<"要修改的学生在文件不存在！" <<endl;else{ofstream out("e:\\studentfile.txt");if(!out){ cout<<"打开学生信息文件失败！"<<endl;return ;}for(int k=0;k<n;k++){ out.seekp(k*sizeof(student),ios::beg);out.write((char*)&stu[k],sizeof(student));}out.close();}break;}case 2:case 3:case 4:case 5: return ;}system("pause");}}void saccount(){ ifstream ifs("e:\\studentfile.txt");if(!ifs){cout<<"打开文件失败！";system("pause");return ;}int i=0;student s;ifs.read((char*)&s,sizeof(student));while(!ifs.eof()){i++;ifs.read((char*)&s,sizeof(student));}ifs.close();cout<<"学生："<<i<<"人"<<endl;ifs.close();system("pause");}void sdisplay(){ ifstream in("e:\\studentfile.txt",ios::in);if(!in){cout<<"打开学生信息文件失败！"<<endl;return ;}student stu;in.read((char*)&stu,sizeof(student));while(!in.eof()){ cout<<stu<<endl;in.read((char*)&stu,sizeof(student));}in.close();system("pause");}class course{ public:int cno;char cname[20];char cxz[10];int zxs;int xf;char kcxq[10];int xxrs;//public:friend void cadd();friend void cselect();friend void cupdate();friend void cdelet();friend void caccount();friend void cdisplay();friend istream & operator >> (istream & in, course &cou){in>>o>>ame>>cou.cxz>>cou.zxs>>cou.xf>>cou.kcxq>>cou.xxrs;return in;}friend ostream & operator <<(ostream & out,course &cou){ out<<o<<" "<<ame<<" "<<cou.cxz<<" "<<cou.zxs<<" "<<cou.xf<<" "<<cou.kcxq<<" "<<cou.xxrs<<endl;return out;}friend void xkadd();};void cadd(){ int flag1=0;course c;cout<<"请输入要添加的课程的课程代码、课程名称、课程性质、总学时、学分、开课学期、选修人数"<<endl;cin>>c;ifstream in("e:\\coursefile.txt");if(!in){cout<<"打开课程信息文件失败！"<<endl;return ;}course cou;in.read((char*)&cou,sizeof(course));while(!in.eof()){ if(o==o) {flag1=1; break;}in.read((char*)&cou,sizeof( course));}in.close();if(flag1==1) cout<<"该课程已经在文件中存在不允添加！" <<endl; else{ ofstream out("e:\\coursefile.txt",ios::app);out.write((char*)&c,sizeof(course));out.close();}system("pause");}void cselect(){while(1){ system("cls");cout<<"*********** 请选择要查询的类别：*************"<<endl;cout<<"*********** 按课程编号请按1：************* "<<endl;cout<<"*********** 按课程名称请按2：*************"<<endl;cout<<"*********** 返回上一级界面请按3：*************"<<endl;int sn;cin>>sn;while(sn>3||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;ifstream in("e:\\coursefile.txt");if(!in){ cout<<"打开课程信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的课程的编号"<<endl;cin>>no;course ke;in.read((char*)&ke,sizeof(course));while(!in.eof()){ if(no==o) {cout<<ke<<endl; flag=1;} in.read((char*)&ke,sizeof(course));//if(no==ke. char*)&ke,sizeof(course));}break;}case 2: {char name[25];cout<<"请输入要查询的课程的名称"<<endl;cin>>name;course ke;in.read((char*)&ke,sizeof(course));while(!in.eof()){ if(strcpy(name,ame)==0) {cout<<ke<<endl; flag=1;}in.read((char*)&ke,sizeof(course));}break;}case 3: return ;}in.close();if(flag==0) cout<<"要查询的课程在文件不存在！" <<endl;system("pause");}}void cupdate(){ while(1){ system("cls");cout<<"***********请选择按下列类别查询后修改：*************"<<endl;cout<<"*********** 按课程编号请按1：************* "<<endl; cout<<"*********** 按课程名称请按2：*************"<<endl;cout<<"*********** 按课程性质请按3：*************"<<endl;cout<<"*********** 按课程学分请按4：*************"<<endl;cout<<"*********** 返回上一级界面请按5：*************"<<endl;int sn;cin>>sn;while(sn>5||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;fstream in("e:\\studentfile.txt",ios::in|ios::out);if(!in){ cout<<"打开课程信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的课程的编号"<<endl;cin>>no;course k;int i=0;in.seekg(i*sizeof(course),ios::beg);in.read((char*)&k,sizeof(course));while(!in.eof()){ if(no==o){ cout<<k<<endl;cout<<"请输入要修改的课程的编号，名称，性质，学分"<<endl;cin>>k;in.seekp(i*sizeof(course),ios::beg);in.write((char*)&k,sizeof(course));flag=1;}i++;in.seekg(i*sizeof(course),ios::beg);in.read((char*)&k,sizeof(course));}break;}case 2: {int no;cout<<"请输入要查询的学生的学号"<<endl;cin>>no;student stu;int i=0;in.seekg(i*sizeof(student),ios::beg);in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(no==stu.sno){ cout<<stu<<endl;cout<<"请输入要修改的的课程的编号，名称，性质，学分"<<endl;cin>>stu;in.seekp(i*sizeof(student),ios::beg);in.write((char*)&stu,sizeof(student));flag=1;}i++;in.seekg(i*sizeof(student),ios::beg);in.read((char*)&stu,sizeof(student));}break;}case 3: return ;}in.close();if(flag==0) cout<<"要修改的选课信息在文件不存在！" <<endl;system("pause");}}void cdelet(){while(1){ system("cls");cout<<"***********请选择按下列类别查询后删除：*************"<<endl;cout<<"*********** 按课程编号请按1：************* "<<endl;cout<<"*********** 按课程名称请按2：*************"<<endl;cout<<"*********** 返回上一级界面请按3：*************"<<endl;int sn;cin>>sn;while(sn>3||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;course k[20];int flag=0;switch(sn){case 1: { ifstream in("e:\\coursefile.txt");if(!in){ cout<<"打开课程信息文件失败！"<<endl;return ;}int n=0;in.read((char*)&k[n],sizeof(course));while(!in.eof()){ n++;in.read((char*)&k[n],sizeof(course));}in.close();int no;cout<<"请输入要删除的课程的编号"<<endl;cin>>no;for(int i=0;i<n;i++){ if(no==k[i].cno){ cout<<k[i]<<endl;cout<<"是否要删除该课程的信息！"<<endl;char ch;cin>>ch;if( ch='Y'||ch=='y'){for(int j=i;j<n;j++)k[j]=k[j+1];n--;}flag=1;}}if(flag==0) cout<<"要修改的课程在文件不存在！" <<endl;else{ofstream out("e:\\coursefile.txt");if(!out){ cout<<"打开课程信息文件失败！"<<endl;return ;}for(int i=0;i<n;i++){ out.seekp(i*sizeof(course),ios::beg);out.write((char*)&k[i],sizeof(course));}out.close();}break;}case 2:case 3:case 4:case 5: return ;}system("pause");}}void caccount(){ ifstream ifs("d:\\coursetfile.txt");if(!ifs){cout<<"打开文件失败！";system("pause");return ;}int i=0;course ke;ifs.read((char*)&ke,sizeof(course));while(!ifs.eof()){ i++;ifs.read((char*)&ke,sizeof(course));}ifs.close();cout<<"课程："<<i<<"门"<<endl;ifs.close();system("pause");}void cdisplay(){ ifstream in("e:\\coursefile.txt");if(!in){cout<<"打开课程信息文件失败！"<<endl;return ;}course cou;in.read((char*)&cou,sizeof( course));while(!in.eof()){ cout<<cou;in.read((char*)&cou,sizeof( course));}in.close();system("pause");}class situaction{ public:int sno;int cno;int score;// public:friend void xkadd();friend void xkselect();friend void xkupdate();friend void xkdelet();friend void xkaccount();friend void xkdisplay();friend istream & operator >> (istream & in, situaction &si){ in>>si.sno>>o;si.score=0;return in;}friend ostream & operator <<(ostream & out,situaction &si){ out<<si.sno<<" "<<o<<" "<<si.score<<endl;return out;}};void xkadd(){ situaction xk;cout<<"请输入要选修的学号、课程号"<<endl;cin>>xk;int flag1=0, flag2=0;ifstream in1("e:\\studentfile.txt");if(!in1){cout<<"打开学生信息文件失败！"<<endl;return ;}student stu;in1.read((char*)&stu,sizeof(student));while(!in1.eof()){ if(xk.sno==stu.sno) {flag1=1; break;}in1.read((char*)&stu,sizeof(student));}in1.close();if(flag1==0) cout<<"该学生不存在不允选课！" <<endl; else{ course cou;ifstream in2("e:\\coursefile.txt");if(!in2){cout<<"打开课程文件失败！"<<endl;return ;}in2.read((char*)&cou,sizeof(course));while(!in2.eof()){ if(o==o) {flag2=1; break;}in2.read((char*)&cou,sizeof(course));}in2.close();if(flag2==0) cout<<"该课程不存在不允选课！" <<endl;else{ situaction si;int scount=0,ccount=0;ifstream in3("e:\\situationfile.txt");if(!in3){cout<<"打开选课文件失败！"<<endl;return ;}in3.read((char*)&si,sizeof(situaction));while(!in3.eof()){ if(xk.sno==si.sno) ccount++;if(o==o) scount++;in3.read((char*)&si,sizeof(situaction));}in3.close();if(cou.xxrs<=scount) cout<<"该课程人数已满不允选课！" <<endl;else if(count<=ccount) cout<<"该学生已选满"<<count<<"不允选课！" <<endl;else{ ofstream out("e:\\situactionfile.txt",ios::app);out.write((char*)&xk,sizeof(situaction));out.close();}}}system("pause");void xkselect(){while(1){ system("cls");cout<<"*********** 请选择要查询的类别：*************"<<endl;cout<<"*********** 按学生编号请按1：************* "<<endl;cout<<"*********** 按课程编号请按2：************* "<<endl;cout<<"*********** 返回上一级界面请按3：*************"<<endl;int sn;cin>>sn;while(sn>3||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;ifstream in("e:\\situactionfile.txt");if(!in){ cout<<"打开选课信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的学生的学号"<<endl;cin>>no;situaction stu;in.read((char*)&stu,sizeof(situaction));while(!in.eof()){ if(no==stu.sno) {cout<<stu<<endl; flag=1;}in.read((char*)&stu,sizeof(situaction));}break;}case 2: {int no;cout<<"请输入要查询的课程的编号"<<endl;cin>>no;situaction ke;in.read((char*)&ke,sizeof(situaction));while(!in.eof()){ if(no==o) {cout<<ke<<endl; flag=1;}in.read((char*)&ke,sizeof(situaction));// if(no==ke. char*)&ke,sizeof(course));}break;}case 3: return ;}in.close();if(flag==0) cout<<"要查询的选课在文件不存在！" <<endl;system("pause");}}void xkupdate(){while(1){ system("cls");cout<<"***********请选择按下列类别查询后修改：*************"<<endl;cout<<"*********** 按课程编号请按1：************* "<<endl;cout<<"*********** 按学生学号请按2：*************"<<endl;cout<<"*********** 返回上一级界面请按3：*************"<<endl;int sn;cin>>sn;while(sn>3||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;fstream in("e:\\situactionfile.txt",ios::in|ios::out);if(!in){ cout<<"打开选课信息文件失败！"<<endl;return ;}int flag=0;switch(sn){case 1: {int no;cout<<"请输入要查询的课程的编号"<<endl;cin>>no;situaction si;int i=0;in.seekg(i*sizeof(situaction),ios::beg);in.read((char*)&si,sizeof(situaction));while(!in.eof()){ if(no==o){ cout<<si<<endl;cout<<"请输入要修改的选课信息的学生学号，选课信息，成绩"<<endl;cin>>si;in.seekp(i*sizeof(situaction),ios::beg);in.write((char*)&si,sizeof(situaction));flag=1;}i++;in.seekg(i*sizeof(situaction),ios::beg);in.read((char*)&si,sizeof(situaction));}break;}case 2: {int no;cout<<"请输入要查询的学生的学号"<<endl;cin>>no;student stu;int i=0;in.seekg(i*sizeof(student),ios::beg);in.read((char*)&stu,sizeof(student));while(!in.eof()){ if(no==stu.sno){ cout<<stu<<endl;cout<<"请输入要修改的选课信息的学生学号，选课信息，成绩"<<endl;cin>>stu;in.seekp(i*sizeof(situaction),ios::beg);in.write((char*)&stu,sizeof(situaction));flag=1;}i++;in.seekg(i*sizeof(situaction),ios::beg);in.read((char*)&stu,sizeof(situaction));}break;}case 3: return ;}in.close();if(flag==0) cout<<"要修改的课程在文件不存在！" <<endl;system("pause");}}void xkdelet(){while(1){ system("cls");cout<<"***********请选择按下列类别查询后删除：*************"<<endl;cout<<"*********** 按学生学号请按1：************* "<<endl;cout<<"*********** 按课程编号请按2：*************"<<endl;cout<<"*********** 返回上一级界面请按3：*************"<<endl;int sn;cin>>sn;while(sn>3||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;student stu[20];course k[20];int flag=0;switch(sn){case 1: { ifstream in("e:\\situactionfile.txt");if(!in){ cout<<"打开学生信息文件失败！"<<endl;return ;}int n=0;in.read((char*)&stu[n],sizeof(student));while(!in.eof()){ n++;in.read((char*)&stu[n],sizeof(student));}in.close();int no;cout<<"请输入要删除的学生的学号"<<endl;cin>>no;for(int i=0;i<n;i++){ if(no==stu[i].sno){ cout<<stu[i]<<endl;cout<<"是否要删除该学生的选课信息！"<<endl;char ch;cin>>ch;if( ch='Y'||ch=='y'){for(int j=i;j<n;j++)stu[j]=stu[j+1];n--;}flag=1;}}if(flag==0) cout<<"要修改的学生在文件不存在！" <<endl;else{ofstream out("e:\\studentfile.txt");if(!out){ cout<<"打开学生信息文件失败！"<<endl;return ;}for(int k=0;k<n;k++){ out.seekp(k*sizeof(student),ios::beg);out.write((char*)&stu[k],sizeof(student));}out.close();}break;}case 2: { ifstream in("e:\\situactionfile.txt");if(!in){ cout<<"打开课程信息文件失败！"<<endl;return ;}int n=0;in.read((char*)&k[n],sizeof(course));while(!in.eof()){ n++;in.read((char*)&k[n],sizeof(course));}in.close();int no;cout<<"请输入要删除的课程的编号"<<endl;cin>>no;for(int i=0;i<n;i++){ if(no==k[i].cno){ cout<<k[i]<<endl;cout<<"是否要删除该课程的信息！"<<endl;char ch;cin>>ch;if( ch='Y'||ch=='y'){for(int j=i;j<n;j++)k[j]=k[j+1];n--;}flag=1;}}if(flag==0) cout<<"要修改的课程在文件不存在！" <<endl;else{ofstream out("e:\\coursefile.txt");if(!out){ cout<<"打开课程信息文件失败！"<<endl;return ;}for(int i=0;i<n;i++){ out.seekp(i*sizeof(course),ios::beg);out.write((char*)&k[i],sizeof(course));}out.close();}break;}system("pause");}}}void xkaccount(){ ifstream ofs("e:\\situactionfile.txt");if(!ofs){ cout<<"打开文件失败！";system("pause");return ;}int i=0;int sn=0,sscore=0;int =0,cscore=0;int sno;cout<<"输入要统计的学生编号"<<endl;cin>>sno;int cno;cout<<"输入要统计的课程编号"<<endl;cin>>cno;situaction si;ofs.read((char*)&si,sizeof(situaction));while(!ofs.eof()){ if(si.sno ==sno){ sn++; sscore+=si.score;}if(o ==cno){ ++; cscore+=si.score;}ofs.read((char*)&si,sizeof(situaction));}ofs.close();cout<<sno<<"同学已经选课："<<sn<<"门"<<"其平均成绩："<<(float)sscore/sn<<endl;cout<<cno<<"门课程已经选课："<<<<"人"<<"该课程的平均成绩："<<(float)cscore/<<endl;ofs.close();system("pause");}void xkdisplay(){ifstream in("e:\\situactionfile.txt");if(!in){cout<<"打开课程信息文件失败！"<<endl;return ;}situaction si;in.read((char*)&si,sizeof(situaction));while(!in.eof()){ cout<<si;in.read((char*)&si,sizeof( situaction));}in.close();system("pause");}void addmenu(){while(1){ system("cls");cout<<"***********请选修要添加信息的类别：*************"<<endl;cout<<"*********** 学生信息添加请按1：************* "<<endl;cout<<"*********** 课程信息添加请按2：*************"<<endl;cout<<"*********** 选课信息添加请按3：*************"<<endl;cout<<"*********** 返回主界面请按4：*************"<<endl;int sn;cin>>sn;while(sn>4||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;switch(sn){case 1: sadd(); break;case 2: cadd(); break;case 3: xkadd(); break;case 4: return ;}}system("pause");}void selectmenu(){while(1){ system("cls");cout<<"***********请选修要查询信息的类别：*************"<<endl;cout<<"*********** 学生信息查询请按1：************* "<<endl;cout<<"*********** 课程信息查询请按2：*************"<<endl;cout<<"*********** 选课信息查询请按3：*************"<<endl;cout<<"*********** 返回主界面请按4：*************"<<endl;int sn;cin>>sn;while(sn>4||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;switch(sn){case 1: sselect(); break;case 2: cselect(); break;case 3: xkselect(); break;case 4: return ;}}system("pause");}void deletmenu(){while(1){ system("cls");cout<<"***********请选修要删除信息的类别：*************"<<endl;cout<<"*********** 学生信息删除请按1：************* "<<endl;cout<<"*********** 课程信息删除请按2：*************"<<endl;cout<<"*********** 选课信息删除请按3：*************"<<endl;cout<<"*********** 返回主界面请按4：*************"<<endl;int sn;cin>>sn;while(sn>4||sn<1){cout<<"选择的数据无效，请重新输入："<<endl;cin>>sn;}cout<<endl;switch(sn){case 1: sdelet(); break;case 2: cdelet(); break;case 3: xkdelet(); break;case 4: return ;}}system("pause");。