50分！求助

Help！

#include <bits/stdc++.h>
using namespace std;
int n;
struct pp{
    int grade1,grade2,grade3,id,all;
}a[310];
bool cmp(pp a,pp b);
int main(){
    scanf("%d",&n);
    for(int i = 0;i<n;i++){
        scanf("%d%d%d",&a[i].grade1,&a[i].grade2,&a[i].grade3);
        a[i].all = a[i].grade1+a[i].grade2+a[i].grade3;
        a[i].id = i+1;
    }
    sort(a,a+n,cmp);
    for(int i = 0;i<5;i++){
        printf("%d %d\n",a[i].id,a[i].all);
    }
    return 0;
}
bool cmp(pp a,pp b){
    return a.all>b.all;
}