Menghitung Nilai IPK

Konstruksi data --> struck jmlipk{
                                char nama[100];
                                char nim[100];
                                int nilai [100][100];
                                int sks[100][100];
                                int ipk1[100][100];
                                string makul[100][100]
                                int jml_makul;
                                int jml_nilai;
                                }ipk;

Menghitung IPK :
#include <iostream>
using namespace std;

struct jmlipk{
char nama[100];
char nim[100];
int nilai[100][100];
int sks[100][100];
int ipk1[100][100];
string makul[100][100];
int jml_makul;
int jml_nilai;
}ipk;

int main(){
 int i, j;
 float jml_ipk, jml_sks;
 cout<<"=====================================\n";
 cout<<"[ Note   : Nilai Dalam Bentuk Angka ]\n";
 cout<<"[        A=4                        ]\n";
 cout<<"[        B=3                        ]\n";
 cout<<"[        C=2                        ]\n";
 cout<<"[        D=1                        ]\n";
 cout<<"[        E=0                        ]\n";
 cout<<"=====================================\n";
 cout<<"Nama          :";cin>>ipk.nama;
 cout<<"NIM           :";cin>>ipk.nim;
 cout<<"Jumlah Makul  :";cin>>ipk.jml_makul;
 for (i=0;i<ipk.jml_makul;i++){
  for (j=0;j<1;j++){
  cout<<"Makul         :";cin>>ipk.makul[i][j];
  cout<<"Nilai         :";cin>>ipk.nilai[i][j];
  cout<<"Sks           :";cin>>ipk.sks[i][j];
  cout<<"\n";
 }
}
 for (i=0;i<ipk.jml_makul;i++){
  for (j=0;j<1;j++){
   ipk.ipk1[i][j]=ipk.sks[i][j]*ipk.nilai[i][j];
  }
 }
 for (i=0;i<ipk.jml_makul;i++){
  for (j=0;j<1;j++){
   jml_sks=jml_sks+ipk.sks[i][j];
  }
 }
 for (i=0;i<ipk.jml_makul;i++){
  for (j=0;j<1;j++){
   ipk.jml_nilai=ipk.jml_nilai+ipk.ipk1[i][j];
  }
 }
 jml_ipk = ipk.jml_nilai/jml_sks;
 cout<<"================================\n";
 cout<<" Nama       : "<<ipk.nama<<" \n";
 cout<<" NIM        : "<<ipk.nim <<" \n";
 cout<<" Jumlah SKS : "<<jml_sks<<" \n";
 cout<<" Ipk        : "<<jml_ipk<<" \n";
 cout<<"================================";
 return 0;
 }