menghitug nilai akhir

HitungNilai.cpp

#include <iostream>
#include <conio.h>
#include <string>

using namespace std;
struct Nilai {
	double tugas;
	double kuis;
	double mid;
	double uas;
	char nilai_akhir;
};
struct Mahasiswa {
	char nama[40];
	char nim[11];
	char kelas[11];
	Nilai nilai;
};//11.12.5800
Mahasiswa mhs;
int main() {
	//Input Data mahasiswa
	cout << "Masukkan Data Mahasiswa : "<<endl;
	cout << "Nama \t\t: "; 
	cin.getline(mhs.nama, sizeof(mhs.nama) / sizeof(mhs.nama[40]));
	cout << "NIM \t\t: ";
	cin.getline(mhs.nim, sizeof(mhs.nim) / sizeof(mhs.nim[11]));
	cout << "Kelas \t\t: ";
	cin.getline(mhs.kelas, sizeof(mhs.kelas) / sizeof(mhs.kelas[11]));
	cout << "Nilai rata - rata tugas : ";
	cin >> mhs.nilai.tugas;
	cout << "Nilai rata - rata kuis \t: ";
	cin >> mhs.nilai.kuis;
	cout << "Nilai mid \t: ";
	cin >> mhs.nilai.mid;
	cout << "Nilai uas \t: ";
	cin >> mhs.nilai.uas;

	//Mencari nilai akhir 
	double jml_nilai_akhir = ((mhs.nilai.tugas * 10) / 100) +
		((mhs.nilai.kuis * 20) / 100) +
		((mhs.nilai.mid * 30) / 100) +
		((mhs.nilai.uas * 40) / 100);

	//Menentukan nilai 
	if (jml_nilai_akhir > 85)
		mhs.nilai.nilai_akhir = 'A';
	else if (jml_nilai_akhir <= 85 && jml_nilai_akhir > 70)
		mhs.nilai.nilai_akhir = 'B';
	else if (jml_nilai_akhir <= 70 && jml_nilai_akhir > 55)
		mhs.nilai.nilai_akhir = 'C';
	else if (jml_nilai_akhir <= 55 && jml_nilai_akhir > 40)
		mhs.nilai.nilai_akhir = 'D';
	else if (jml_nilai_akhir <= 40)
		mhs.nilai.nilai_akhir = 'E';

	//menampilkan nilai akhir mahasiswa
	cout << "----------------------------------------------------\n";
	cout << "              Nilai Akhir Mahasiswa\n";
	cout << "----------------------------------------------------\n\n";

	cout << "Nama  : " << mhs.nama << endl;
	cout << "NIM   : " << mhs.nim << endl;
	cout << "Kelas : " << mhs.kelas << endl;
	cout << "Nilai : " << mhs.nilai.nilai_akhir << endl;

	getch();
}