This article uses the list data structure of the STL class library to complete the student management system, using the sorting in the linked list, and sorting through the sort function of the list class library.
- Note: At this time, the collation function is defined as a class static member function, which is equivalent to a global function
- The function pointer is defined as
BY_FUNC ps[] = { CStudent::byNumb,CStudent::byName,CStudent::byMath };
Define the CStudent class in C++
file name:Student.h
#pragma once
#include <list>
typedef struct SUser
{
int nNumb;
char sName[20];
float fMath;
}DATA;
//using namespace std; //头文件中最好不要using
typedef bool (*BY_FUNC)(DATA& q, DATA& m);
class CStudent
{
std::list<DATA> m_list;
int Menu();
int Input();
bool Delete();
void Modify();
void Print();
//void Sort(BY_FUNC pFunc);
int SortMenu();
void Load();
void Save();
//void PrintPS(POSITION* ps);
bool Check(int nNumb);
int FindMenu();
//void FindByNumb();
static bool byNumb(DATA& q, DATA& m) // 静态成员函数
{
return q.nNumb < m.nNumb;
}
static bool byName(DATA& q, DATA& m)
{
return strcmp(q.sName, m.sName) < 0;
}
static bool byMath(DATA& q, DATA& m)
{
return q.fMath > m.fMath;
}
public:
CStudent();
~CStudent();
void Start();
};
Class member function implementation
file name:Student.cpp
#define _CRT_SECURE_NO_WARNINGS
#include "Student.h"
#include <iostream>
#include <conio.h>
using namespace std;
bool CStudent::Check(int nNumb)
{
list<DATA>::iterator it = m_list.begin();
while (it!=m_list.end())
{
if (it->nNumb == nNumb)
return true;
++it;
}
return false;
}
int CStudent::FindMenu()
{
return 0;
}
CStudent::CStudent()
{
}
CStudent::~CStudent()
{
}
void CStudent::Start()
{
Load();
while (Menu())
;
}
int CStudent::SortMenu()
{
system("cls");
puts("1.按学号排序");
puts("2.按姓名排序");
puts("3.按成绩排序");
puts("4.不排序");
puts("0.返回主菜单");
int i = 0;
cin >> i;
BY_FUNC ps[] = {
CStudent::byNumb,CStudent::byName,CStudent::byMath };
switch (i)
{
case 1:
case 2:
case 3:
m_list.sort(ps[i - 1]);
case 4:
Print();
default:
return i;
}
return i;
}
void CStudent::Load()
{
FILE* pf = fopen("stud.lv", "r");
if (!pf)
{
puts("加载文件时失败！");
system("pause");
return;
}
DATA t;
while (fread(&t, 1, sizeof(DATA), pf) == sizeof(DATA))
m_list.push_back(t);
fclose(pf);
}
void CStudent::Save()
{
FILE* pf = fopen("stud.lv", "w");
if (!pf)
{
puts("保存文件时失败！");
system("pause");
return;
}
list<DATA>::iterator it = m_list.begin();
while (it!=m_list.end())
{
fwrite(&(*it), 1, sizeof(DATA), pf);
++it;
}
fclose(pf);
}
int CStudent::Menu()
{
system("cls");//clear screen
puts("\n\t\t1、浏览所有信息");
puts("\t\t2、添加信息");
puts("\t\t3、删除信息");
puts("\t\t4、修改信息");
puts("\t\t5、查找信息");
puts("\t\t0、退出");
printf("\t\t请选择：");
int i = 0;
cin >> i;
switch (i)
{
case 1:
while (SortMenu())
;
break;
case 2:
while (Input())
;
break;
case 3:
while (Delete())
;
break;
case 4:
Modify();
break;
case 5:
while (FindMenu())
;
}
return i;
}
int CStudent::Input()
{
cout << "请输入学号：";
DATA d;
while (true)
{
cin >> d.nNumb;
if (Check(d.nNumb))
cout << "学号已存在，请重新输入：";
else
break;
}
cout << "请输入姓名和数学成绩（空格间隔）：";
cin >> d.sName >> d.fMath;
m_list.push_back(d);
Save();
Print();
cout << "是否继续添加？[y/n]";
rewind(stdin);
char c = getchar();
return c == 'y' || c == 'Y';
}
bool CStudent::Delete()
{
int nNumb;
Print();
cout << "请输入要删除的学号：";
cin >> nNumb;
list<DATA>::iterator it = m_list.begin();
while (it!=m_list.end())
{
if (it->nNumb == nNumb)
{
m_list.erase(it);
Print();
cout << "删除成功！" << endl;
system("pause");
Save();
return false;
}
++it;
}
cout << "你输入的学号不存在，是否继续删除？[y/n]";
char c = _getch();
putchar(c);
puts("");
return 'y' == c || 'Y' == c;
}
void CStudent::Modify()
{
}
void CStudent::Print()
{
list<DATA>::iterator it = m_list.begin();
cout << "学号\t姓名\t成绩" << endl;
while (it!=m_list.end())
{
cout << it->nNumb << "\t" << it->sName << "\t" << it->fMath << endl;
++it;
}
system("pause");
}
Main function
file name:main.cpp
#include "Student.h"
void main()
{
CStudent st;
st.Start();
}