怎么改才能让这个程序能实现按平均成绩降序排序
怎么改才能让这个程序能实现按平均成绩降序排序
#include<iomanip>
#include<iostream>
using namespace std;
#include<string>
class student{
public:
void getinfo();
void display();
void sort(student *p);
private:
char name[9];
int english,computer,mathematics;
double average;
};
void student::getinfo ()
{
cout<<"姓名";cin>>name;
cout<<"英语成绩";cin>>english;
cout<<"计算机成绩";cin>>computer;
cout<<"数学成绩";cin>>mathematics;
average=(english+computer+mathematics)/3.0;
}
void student::display ()
{ cout<<setw(8)<<name<<":英语="<<setw(3)<<english<<",计算机="
<<setw(3)<<computer<<",数学="<<setw(3)<<mathematics
<<"平均成绩="<<setw(5)<<setprecision(4)<<average<<endl;
}
void student::sort (student *p)
{
int tmp;
double temp;
char tname[9];
if(average>p->average )
{
strcpy(tname,name);strcpy(name,p->name );strcpy(p->name ,tname);
tmp=english;english=p->english ;p->english =tmp;
tmp=computer;computer=p->computer ;p->computer=tmp;
tmp=mathematics;mathematics=p->mathematics ;p->mathematics =tmp;
temp=average;average=p->average ;p->average=temp;
}
}
const int n=3;
void main()
{
student *ST[n];
for(int i=0;i<n;i++)
{
ST[i]=new student;
cout<<"学生"<<i+1<<endl;
ST[i]->getinfo();
}
int j;
for(j=0;j<n-1;j++)
for(i<0;i<n-1-j;i++)
ST[i]->sort(ST[i+1]);
cout<<"\n排序结果\n";
for(i=0;i<n;i++)
{ST[i]->display();delete ST[i];}
}[/size]
[解决办法]
#include<iomanip>#include<iostream>#include<string>using namespace std;class student{public: void getinfo(); void display(); void sort(student *p);private: void swap(student *p) { int tmp; double temp; char tname[9]; strcpy(tname,name);strcpy(name,p->name );strcpy(p->name ,tname); tmp=english;english=p->english ;p->english =tmp; tmp=computer;computer=p->computer ;p->computer=tmp; tmp=mathematics;mathematics=p->mathematics ;p->mathematics =tmp; temp=average;average=p->average ;p->average=temp; }private: char name[9]; int english,computer,mathematics; double average;};void student::getinfo (){ cout<<"姓名";cin>>name; cout<<"英语成绩";cin>>english; cout<<"计算机成绩";cin>>computer; cout<<"数学成绩";cin>>mathematics; average=(english+computer+mathematics)/3.0;}void student::display (){ cout<<setw(8)<<name<<":英语="<<setw(3)<<english<<",计算机=" <<setw(3)<<computer<<",数学="<<setw(3)<<mathematics <<"平均成绩="<<setw(5)<<setprecision(4)<<average<<endl;}void student::sort (student *p){ /* int tmp; double temp; char tname[9]; */ //要降序改下这里就可以了 if(average < p->average ) { /*这样的代码最好专门交给一个swap函数去处理 或者重载赋值操作符 strcpy(tname,name);strcpy(name,p->name );strcpy(p->name ,tname); tmp=english;english=p->english ;p->english =tmp; tmp=computer;computer=p->computer ;p->computer=tmp; tmp=mathematics;mathematics=p->mathematics ;p->mathematics =tmp; temp=average;average=p->average ;p->average=temp; */ //p->swap(this); swap(p); }}const int n=3;int main(){ student *ST[n]; int i= 0; //for(int i=0;i<n;i++) for(i=0;i<n;i++) { ST[i]=new student; cout<<"学生"<<i+1<<endl; ST[i]->getinfo(); } int j; for(j=0;j<n-1;j++) { //楼主这个i<0害人不浅 for(i = 0;i<n-1-j;i++) ST[i]->sort(ST[i+1]); } cout<<"\n排序结果\n"; //i 无声明 上面的i在for循环结束后就死亡了 for(i=0;i<n;i++) { ST[i]->display(); delete ST[i]; } system("pause"); return 0;}
[解决办法]
楼上的是用的冒泡排序算法
我也写了一个， 很久没写， 你试试，我的对不对
class Student{public: void getinfo(); void display(); private: string name; int english,computer,mathematics; double average; friend void SwapStudent(Student & obj1, Student &obj2); // 交换函数 friend void BubbleSort(Student stu[], int count); //冒泡排序};void Student::getinfo (){ cout<<"姓名";cin>>name; cout<<"英语成绩";cin>>english; cout<<"计算机成绩";cin>>computer; cout<<"数学成绩";cin>>mathematics; average=(english+computer+mathematics)/3.0;}void Student::display (){ cout<<setw(8)<<name<<":英语="<<setw(3)<<english<<",计算机=" <<setw(3)<<computer<<",数学="<<setw(3)<<mathematics <<"平均成绩="<<setw(5)<<setprecision(4)<<average<<endl;} void BubbleSort(Student stu[], int n) //冒泡排序 { //每一趟交换，把最大的哪项交换到数组的最后面 bool flag=false; //交换标志，为true 的时候，表示，发生交换;一趟下来，如果flag值为false，表示所有都排序好. int i,j; for( i=0; i< n-1; i++) { flag=false; for(j=0; j< n-1- i; j++) //扫描每一趟 { //进行比较 if( stu[j].average<stu[j].average ) { SwapStudent(stu[j],stu[j+1]); //发生交换 flag=true; } } if( flag ==false) break; } }
[解决办法]
我觉得LZ有不好写代码的习惯，我一贴到我的IDE上，看到挺乱的，建议养成好的代码习惯