Contoh program sederhana C++ penginputan niai siswa dengan methode Fungsi

#include "string.h"
#include "stdio.h"
#include "iostream.h"

char NH(double na);
double NA(int mid,int uas);
void main(){
      char nama[30];char nis[8];char ket[10];
      int mid,uas;double na;

      cout<<"input Nilai mahasiswa :"<<endl;
      cout<<"__________________________________"<<endl;
      cout<<"Nis :";gets(nis);
      cout<<"Nama :";gets(nama);
      cout<<"Nilai mid :";cin>>mid;
      cout<<"Nilai uas :";cin>>uas;
      na=NA(mid,uas);
      cout<<"nilai angka :"<<na<<endl;
      cout<<"nilai huruf :"<<NH(na)<<endl;
      if(NH(na)=='E') strcpy(ket,"gagal");
      else strcpy(ket,"lulus");
      cout<<"keterangan :"<<ket;
      }
      double NA(int mid,int uas){
          return(0.4*mid+0.6*uas);
          }
      char NH(double xna){
          char x;
          if(xna>=80)x='A';
          else if(xna>=70)x='B';
          else if(xna>=60)x='c';
          else if(xna>=50)x='D';
          else x='E';
          return(x);
          }