to calc marks

#include<iostream>
using namespace std;
class student
{
public:
char name[30];
int roll;
int marks[5];
float result;
void getdata();
float displayResult();
};
 void student::getdata ()
  {
   cout<<"\nenter name\t";
    cin>>name;
   cout<<"\nenter rollno\t";
    cin>>roll;
   cout<<"\nenter marks\t";
      for(int i=0;i<5;i++)
         {
      cin>>marks[i];
      cout<<"\t";
         }
  }

 float student::displayResult()

  { int sum=0;
    for(int i=0;i<4;i++)
      {
    sum=sum+marks[i];
      }
     result=sum/5;
   return result;
  }

 int main ()
 {
   student s[34];
for(int j=1;j<=34;j++)
    {
      cout<<"\nEnter detail of  student "<<j<<"\n";
      s[j].getdata();
float r=s[j].displayResult();
    cout<<"\nResult of student\t"<<j<<"\tis\t"<<r<<"\n";
        }
    return 0;
 }