latihan kuis v2

#include <iostream>
#include <stdlib.h>
using namespace std;

int nilai_akhir(int tugas, int uts, int uas){
	return (tugas * 0.5) + (uts * 0.2) + (uas * 0.3);
}
main (){
	int percobaan = 0, nilai_akhir, tugas, uas, uts;
	char nama[50], mata_kuliah[30], dosen[50];
	long nim;
	string password, status, grade;
	do{
		cout << "[!] Masukkan password : "; cin >> password;
		percobaan = percobaan + 1;
		if (percobaan==3){
			cout << "Anda telah salah password 3x,Program berhenti !";
			exit(EXIT_FAILURE);
		}
	}while (password != "akbar2612");
	system("CLS");
		cout << "Selamat datang !!" << endl;
		cout << "Masukkan Nama anda : "; cin >> nama;
		cout << "Masukkan NIM anda : " ; cin >> nim;
		cout << "Masukkan Mata kuliah : "; cin >> mata_kuliah;
		cout << "Dosen anda : "; cin >> dosen;
		cout << "Masukkan nilai tugas : "; cin >> tugas;
		cout << "Masukkan nilai UAS : "; cin >> uas;
		cout << "Masukkan nilai UTS : "; cin >> uts;
		if (tugas > 60){
			status = "Lulus";
		}else{
			cout << " [!] Anda tidak lulus";
			exit(EXIT_FAILURE);
		}
	if (nilai_akhir > 85 && nilai_akhir < 100){
		grade = "A";
		status = "Lulus";
	}else if (nilai_akhir > 75 && nilai_akhir < 84){
		grade = "B";
		status = "Lulus";
	}else if (nilai_akhir > 60 && nilai_akhir < 74){
		grade = "C";
		status = "Lulus";
	}else if (nilai_akhir > 40 && nilai_akhir < 59){
		grade = "D";
		status = "Tidak Lulus";
	}else{
		grade = "E";
		status = " Tidak Lulus";
	}
	system("CLS");
	cout << "Nama : " << nama << endl;
	cout << "NIM : " << nim << endl;
	cout << "Mata kuliah : " << mata_kuliah << endl;
	cout << "Dosen anda : " << dosen << endl;
	cout << "Nilai Akhir anda : " << nilai_akhir << endl;
	cout << "Grade : " << grade << endl;
	cout << "Status : " << status << endl;
}