1404解题思路：重点在于是先排成绩，再排名字，最后排年龄，还是先排年龄，再排名字，最后排成绩。

#include <bits/stdc++.h>
using namespace std;
struct Student{
	string name;
	int age;
	int grade;
}stu[1000];
bool grade_ASC(Student a,Student b)
{
	return a.grade<b.grade;
}
bool name_ASC(Student a,Student b)
{
	return a.name<b.name;
}
bool age_ASC(Student a,Student b)
{
	return a.age<b.age;
}
int main()
{
	int n;
	while(cin>>n)
	{
		for(int i=0;i<n;i++)
		{
			cin>>stu[i].name>>stu[i].age>>stu[i].grade;
		}
		
		
		stable_sort(stu,stu+n,age_ASC);
		stable_sort(stu,stu+n,name_ASC);
		stable_sort(stu,stu+n,grade_ASC);
		for(int i=0;i<n;i++)
		{
			cout<<stu[i].name<<" "<<stu[i].age<<" "<<stu[i].grade<<endl;
		}
	}
 }