建立一个学生类，存放5个学生的数据（学号、姓名、成绩）

采纳后可以帮你完善sort和search的代码

#include <iostream>
#include <string>
using namespace std;
class Student
{
public:
    Student(string n,float s):number(n),score(s){}
    friend void max(Student *);  //声明友元函数
private:
    string number; //将学号声明为字符串
    float score;
};
void max(Student *p)
{
    int i;
    for(i=0;i<5;i++)
    {
        if(p->score<(p+i)->score)
        {
            p=(p+1);  //将指向较大值的指针赋给指向较小值的指针
        }
    }
    cout<<"最高成绩为："<<p->score<<endl;
    cout<<"学生学号为："<<p->number;
}


int main()
{
    Student Stud[5]={
    Student("201024131101",99),
    Student("201024131102",92),
    Student("201024131103",99.5),
    Student("201024131104",95),
    Student("201024131105",93)
    };  //定义一个对象数组数组并初始化对象
    Student *p=Stud;   //定义一个指向对象的指针
    max(p);   //调用函数
    return 0;
}

https://blog.csdn.net/xiao_song_shu/article/details/69252661

// Q753145.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"


#include <iostream>
#include <string>
using namespace std;
class Student
{
public:
    Student(string n, string na, float s):number(n),score(s),name(na) {} //构造函数
    void max(Student *);
    void sort(Student *, int);
    void search(Student *, string, int);
    void display()
    {
        cout << name << " " << number << " " << score << endl;
    }
private:
    string number; //将学号声明为字符串
    string name;
    float score;
};
void Student::max(Student *p)
{
    int i;
    for(i=0;i<5;i++)
    {
        if(p->score<(p+i)->score)
        {
            p=(p+1);  //将指向较大值的指针赋给指向较小值的指针
        }
    }
    cout<<"最高成绩为："<<p->score<<endl;
    cout<<"学生姓名为："<<p->name<<endl;
    cout<<"学生学号为："<<p->number << endl;
}

void Student::sort(Student *p, int n)
{
    for (int i = 0; i < n - 1; i++)
        for (int j = 0; j < n - i - 1; j++)
        {
            if (p[j].score < p[j + 1].score)
            {
                string tn = p[j].number;
                string tna = p[j].name;
                float ts = p[j].score;
                p[j].number = p[j + 1].number;
                p[j].name = p[j + 1].name;
                p[j].score = p[j + 1].score;
                p[j + 1].number = tn;
                p[j + 1].name = tna;
                p[j + 1].score = ts;
            }
        }
}

void Student::search(Student *p, string name, int n)
{
    int found = 0;
    for (int i = 0; i < n - 1; i++)
    {
        if (p[i].name == name) 
        {
            found = 1;
            p[i].display();
        }
    }
    if (!found) cout << "no result" << endl;
}

int main()
{
    Student Stud[5]={
    Student("201024131101", "a",99),
    Student("201024131102", "b",92),
    Student("201024131103", "b",99.5),
    Student("201024131104", "c",95),
    Student("201024131105", "cc",93)
    };  //定义一个对象数组数组并初始化对象
    Student *p=Stud;   //定义一个指向对象的指针
    p->max(p);   //调用函数
    cout << "search b:" << endl;
    p->search(p, "b", 5);
    cout << "sort:" << endl;
    p->sort(p, 5);
    for (int i = 0; i < 5; i++)
        p[i].display();
    return 0;
}

最高成绩为：99.5
学生姓名为：b
学生学号为：201024131103
search b:
b 201024131102 92
b 201024131103 99.5
sort:
b 201024131103 99.5
a 201024131101 99
c 201024131104 95
cc 201024131105 93
b 201024131102 92
Press any key to continue . . .