利用线性链表实现学生成绩管理系统，具体功能：输入、输出、插入、删除、查找、追加、读入、显示、保存、拷贝、排序、索引、分类合计、退出，并能在屏幕上输出操作前后的结果。
1. 写出系统需求分析,并建模。
2. 编程实现,界面友好。
3. 输出操作前后的结果
1.头文件
#define MAX_NUM 10
#include <String>
#include <fstream>
using namespace std;
bool quit = false;
struct StuNode{
int num;
int math, eng, yuwen;
int sum;
StuNode *nextstu;
};
class SInfo{
StuNode *StuListHead;
public:
SInfo(); //构造函数
~SInfo(); //析构函数
void CreatSinfo(); //创建学生信息
void StuInsert(int snum, int smath, int seng, int syuwen); //插入学生信息
void StuDelete(int snum); //删除学生信息
StuNode *StuFind(int snum); //查找学生信息，传入参数学号
void StuModify(int snum, int smath, int seng, int syuwen); //修改学生信息
void StuCopy(StuNode *ptemp, StuNode *p); //学生信息拷贝
void StuSort(char ch);
void StuClassfy(); //分类合计
void StuRead(); //从文件读入学生信息
void StuSave(); //保存学生信息到文件
int IsRead();
void StuQuit();
void ShowInfo(); //遍历输出学生信息
};
int Systemdoor()
{
string username = "Hecoz", password = "password";
string name, temp;
int number = 3;
while (1)
{
cout << " 用 户 名：";
cin >> name;
cout << " 密 码：";
cin >> temp;
if (name != username || temp != password)
{
number--;
if (number >0)
{
cout << " 用户名/密码错误!你还有" << number << "次机会" << endl;
}
else
cout << "用户名/密码错误!" << endl, exit(0);
}
else
{
cout << "********************密码正确********************" << endl<<endl;
return 1;
}
}
}
void ShowMenu()
{
cout << "********************************************" << endl;
cout << "****** 学 生 信 息 系 统 ******" << endl;
cout << "****** 0.安全退出系统 ******" << endl;
cout << "****** 1.文件读入学生信息 ******" << endl;
cout << "****** 2.录入新的学生信息 ******" << endl;
cout << "****** 3.添加新的学生信息 ******" << endl;
cout << "****** 4.删除已有学生信息 ******" << endl;
cout << "****** 5.查找已有学生信息 ******" << endl;
cout << "****** 6.修改已有学生信息 ******" << endl;
cout << "****** 7.已有学生信息排序 ******" << endl;
cout << "****** 8.分类合计学生信息 ******" << endl;
cout << "****** 9.输出所有学生信息 ******" << endl;
cout << "****** 10.保存现有学生信息 ******" << endl;
cout << "\n\t\n\t\t请选择：";
}
SInfo::SInfo() //构造函数
{
StuListHead = new StuNode;
StuListHead->nextstu = NULL;
}
SInfo::~SInfo() //析构函数
{
StuNode *p;
while (StuListHead)
{
p = StuListHead;
StuListHead = StuListHead->nextstu;
delete p;
}
StuListHead = NULL;
}
void SInfo::CreatSinfo() //创建学生信息表
{
int n;
StuNode *p, *s;
p = StuListHead;
cout << "请输入学生人数：";
cin >> n;
for (int i = 1; i <= n; i++)
{
s = new StuNode;
cin >> s->num >> s->math>>s->eng>>s->yuwen;
s->sum = s->math + s->eng + s->yuwen;
s->nextstu = p->nextstu;
p->nextstu = s;
p = p->nextstu;
}
if (p == NULL) //判断学生信息表是否创建成功
{
cout << "创建失败请重新创建！" << endl;
CreatSinfo();
}
}
void SInfo::ShowInfo() //遍历输出
{
StuNode *p;
cout << "学号" << '\t' << "数学" << '\t' << "英语" << '\t' << "语文" << '\t' << "总分" << endl;
for (p = StuListHead->nextstu; p != NULL; p = p->nextstu)
{
cout << p->num << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->sum << endl;
}
}
void SInfo::StuInsert(int snum, int smath,int seng,int syuwen) //插入学生信息（头插法）
{
StuNode *s,*p;
s = new StuNode;
s->num = snum;
s->math = smath;
s->eng = seng;
s->yuwen = syuwen;
s->sum = s->math + s->eng + s->yuwen;
p = StuListHead;
s->nextstu = p->nextstu;
p->nextstu = s;
}
void SInfo::StuDelete(int snum)
{
StuNode *p, *ptemp;
p = StuListHead;
ptemp = p;
while (p->nextstu && p->num!=snum) //循环终止条件为p->nextstu不为空 而且没有找到相应学号的学生
{
ptemp = p;
p = p->nextstu;
}
if (p->num == snum)
{
ptemp->nextstu = p->nextstu;
delete p;
}
else
{
cout << "未找到该学生信息！" << endl;
}
}
StuNode *SInfo::StuFind(int snum)
{
StuNode *p;
p = StuListHead->nextstu;
while (p->nextstu && p->num != snum) //循环终止条件为p->nextstu不为空 而且没有找到相应学号的学生
{
p = p->nextstu;
}
if (p->num == snum)
{
return p;
}
else
{
cout << "未找到该学生信息！" << endl;
return NULL;
}
}
void SInfo::StuModify(int snum, int smath, int seng, int syuwen)
{
StuNode *ItemStu = StuFind(snum); //直接调用查找函数
if (ItemStu != NULL)
{
ItemStu->math = smath;
ItemStu->num = snum;
ItemStu->math = smath;
ItemStu->eng = seng;
ItemStu->yuwen = syuwen;
ItemStu->sum = ItemStu->math + ItemStu->eng + ItemStu->yuwen;
}
}
void SInfo::StuCopy(StuNode *ptemp, StuNode *p) //拷贝学生信息(将p的信息拷贝到ptemp中)
{
if (p == NULL)
{
cout << "拷贝目标为空！" << endl;
}
else
{
ptemp->num = p->num;
ptemp->math = p->math;
ptemp->eng = p->eng;
ptemp->yuwen = p->yuwen;
ptemp->sum = p->sum;
//ptemp->nextstu = p->nextstu; //只是信息拷贝,next不能拷贝否则信息丢失
}
}
void SInfo::StuSort(char ch) //根据 总分排序
{
if (ch == '>')
{
for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)
{
for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)
{
if (p->sum > q->sum)
{
StuNode *ptemp = new StuNode;
StuCopy(ptemp, p);
StuCopy(p, q);
StuCopy(q, ptemp);
}
}
}
}
else if (ch == '<')
{
for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)
{
for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)
{
if (p->sum < q->sum)
{
StuNode *ptemp = new StuNode;
StuCopy(ptemp, p);
StuCopy(p, q);
StuCopy(q, ptemp);
}
}
}
}
else if (ch == 'o')
{
for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)
{
for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)
{
if (p->num < q->num)
{
StuNode *ptemp = new StuNode;
StuCopy(ptemp, p);
StuCopy(p, q);
StuCopy(q, ptemp);
}
}
}
}
else
{
cout << "排序条件出错！" << endl;
}
}
void SInfo::StuClassfy() //根据学生总分分类
{
int grade[5] = {0};
StuNode *p = StuListHead->nextstu;
while (p != NULL)
{
if (89 < p->math)
{
grade[0]++;
}
else if (79 < p->math && p->math < 90)
{
grade[1]++;
}
else if (69 < p->math && p->math < 80)
{
grade[2]++;
}
else if (59 < p->math && p->math < 70)
{
grade[3]++;
}
else
{
grade[4]++;
}
p = p->nextstu;
}
cout << "A" << '\t' << "B" << '\t' << "C" << '\t' << "D" << '\t' << "E" << endl;
for (int i = 0; i < 5; i++)
{
cout << grade[i] << '\t';
}
cout << endl;
}
void SInfo::StuRead() //从文件读入数据
{
StuNode *p;
p = StuListHead;
ifstream in("StudentList.txt");
if (!in) { cout << "没有学生信息，请先录入学生信息!" << endl; return; }
while (!in.eof())
{
int num, math, eng, yuwen, sum;
in >> num >> math >> eng >> yuwen >>sum;
StuInsert(num,math,eng,yuwen);
}
}
void SInfo::StuSave() //保存学生信息
{
StuNode *p;
p = StuListHead->nextstu;
ofstream out("StudentList.txt");
if (!out) { cout << "不能打开文件！" << endl; return; }
while (p != NULL)
{
out << p->num << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->sum << '\n';
p = p->nextstu;
}
}
void SInfo::StuQuit() //学生信息写入文件
{
char choice;
cout << "是否保存学生信息：？（Y/N）";
cin >> choice;
if (choice == 'y' || choice == 'Y')
{
StuSave();
cout << "学生信息已保存..." << endl;
}
}
2.源程序
#include<iostream>
#include "SInfo.h"
#include<cstdlib>
using namespace std;
int main()
{
Systemdoor();
int x = 100, pnum,pmath,peng,pyuwen;
StuNode *pfind;
SInfo stu;
cout <<" ******************************************" << endl;
cout <<" ******************************************" << endl;
cout <<" ****** ******" << endl;
cout <<" ****** 欢迎进入学生信息管理系统 ******" << endl;
cout <<" ****** ******" << endl;
cout <<" ******************************************" << endl;
cout <<" ******************************************" << endl;
while (x != 0)
{
system("pause");
system("cls"); //清屏
ShowMenu();
cin >> x;
switch (x)
{
case 0:
stu.StuQuit();
break;
case 1:
stu.StuRead();
cout << "读入学生信息表：" << endl;
stu.ShowInfo();
break;
case 2:
stu.CreatSinfo();
cout << "请核对输入学生信息！" << endl;
stu.ShowInfo();
break;
case 3:
cout << "请输入添加学生信息：";
cin >> pnum >> pmath >> peng >> pyuwen;
stu.StuInsert(pnum, pmath, peng, pyuwen);
cout << "更新学生信息表..." << endl;
stu.ShowInfo();
break;
case 4:
cout << "请输入要删除学生学号：";
cin >> pnum;
stu.StuDelete(pnum);
cout << "更新学生信息表..." << endl;
stu.ShowInfo();
break;
case 5:
cout << "请输入要查找学生学号：";
cin >> pnum;
pfind = stu.StuFind(pnum);
cout << "查找学生学号：" << pfind->num <<" 数学 "<<pfind->math<<" 英语 "<<pfind->eng<<" 语文 "<<pfind->yuwen <<" 总分 " << pfind->sum << endl;
break;
case 6:
cout << "请输入要修改学生学号：";
cin >> pnum;
cout << "请重新输入学生分数：";
cin >> pmath >> peng >> pyuwen;
stu.StuModify(pnum, pmath, peng, pyuwen);
cout << "修改成功！" << endl;
cout << "更新学生信息表..." << endl;
stu.ShowInfo();
break;
case 7:
cout << "升序排序（1）降序排序（0）学号排序（10）：";
cin >> pnum;
if (pnum == 1)
{
stu.StuSort('<');
stu.ShowInfo();
}
else if (pnum == 0)
{
stu.StuSort('>');
stu.ShowInfo();
}
else if (pnum == 10)
{
stu.StuSort('o');
stu.ShowInfo();
}
else
{
cout << "请输入正确选择！" << endl;
}
break;
case 8:
stu.StuClassfy();
break;
case 9:
stu.ShowInfo();
break;
case 10:
stu.StuSave();
break;
}
}
system("pause");
return 0;
}