样例都没过……

#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
struct stu{
    int num,yw,sx,yy,sum;
}a[305];
bool cmp(stu a,stu b){
    if(a.sum!=b.sum){
        return a.sum>a.sum;
    }else if(a.yw!=b.yw){
        return a.yw>b.yw;
    }else{
        return a.num<b.num;
    }
}
int main(){ 
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i].yw>>a[i].sx>>a[i].yy;
        a[i].sum=a[i].sx+a[i].yw+a[i].yy;
        a[i].num=i;
    }
    sort(a+1,a+1+n,cmp);
    for(int i=5;i>=1;i--){
        cout<<a[i].num<<' '<<a[i].sx+a[i].yw+a[i].yy<<endl;
    }
    return 0;
}

有没有dalao告诉我怎么回事