利用交换算法，解决学生id排序的算法

#include <stdafx.h>

#include <iostream> 

#include <stdlib.h>

#include <cmath>



using namespace std;



struct STUDENT
{ 
	int id;   //学号
	int class_id; //班级
	int score;  //分数
};

void main()

{
	STUDENT stu[6]={{1,2,80},{2,3,90},{3,3,75},{1,1,60},{1,2,85},{2,3,95}};
	
	STUDENT *pStudent = stu;

	STUDENT *pStudentMin = new STUDENT;

	for(int i=0;i<6;i++)

	{
		for(int j=i+1;j<6;j++)
		{
			if ((pStudent+i)->id > (pStudent+j)->id)
			{
				*pStudentMin = *(pStudent+j);
				*(pStudent+j) = *(pStudent+i);
				*(pStudent+i) = *pStudentMin;
			}
		}
	}

	for(int i=0;i<6;i++)

	{
		for(int j=i+1;j<6;j++)
		{
			if ((pStudent+i)->class_id > (pStudent+j)->class_id)
			{
				*pStudentMin = *(pStudent+j);
				*(pStudent+j) = *(pStudent+i);
				*(pStudent+i) = *pStudentMin;
			}
		}
	}

	cout <<setw(4)<<"id"<<setw(12)<<"class_id"<<setw(8)<<"score"<<endl;
	for (int i=0;i<6;i++)
	{
		cout <<setw(4)<<stu[i].id<<setw(12)<<stu[i].class_id<<setw(8)<<stu[i].score<<endl;
	}

	delete pStudentMin;
}