how to solve 4.2

Assalamualaikum w.w.
Algoritma:
Deklarasi banyak,i,x
array int nilai [20]
deklarasi string nama
inputkan banyak mahasiswa
for (int i=1;i<=banyak;i++){
input nama;
input nilai mahasiswa i
if (nilai[20]>=80 || nilai[20]<=100)
ceta nilai = A
else if (nilai[20]>=60 || nilai[20]<80)
cetak nilai = B
else if (nilai[20]>=40 || nilai[20]<60)
cetak nilai = C
else if (nilai[20]>=20 || nilai[20]<40)
cetak nilai = D
else if (nilai[20]>=0 || nilai[20]<20)
cetak nilai = E
end for

program
input c++:

output c++:

wassalamualaikum w.w.
how to solve 4.2
how to solve 4.2