总成绩排序

#include<iostream>
#include<stdio.h>
#include<string>
#include<algorithm>
using namespace std;
struct student
{
    char sno[13];
    string name;
    int grade[3];
    int sum;
};
int cmp(student a,student b)
{ 
    if(a.sum!=b.sum)
        return a.sum>b.sum;//降序
    else
    {
        return a.name<b.name;//升序
    }
}
int main()
{
    int n,i;
    student a[100];
    while(~scanf("%d",&n))
    {
        for(i=0;i<n;i++)
    {
       cin>>a[i].sno>>a[i].name>>a[i].grade[0]>>a[i].grade[1]>>a[i].grade[2];
       a[i].sum=a[i].grade[0]+a[i].grade[1]+a[i].grade[2];
    }
    sort(a,a+n,cmp);
     for(i=0;i<n;i++)
     {
      cout<<a[i].sno<<" "<<a[i].name<<" "<<a[i].grade[0]<<" "<<a[i].grade[1]<<" "<<a[i].grade[2]<<" "<<a[i].sum<<endl;
     }
    }
    return 0;
}