Non-singular matrix Lu decomposition C ++ Program

// Lluu. cpp
// Lu decomposition of the matrix
# Include <iostream>
# Include <fstream>
# Include <cmath>
Using namespace STD;
Class lluu
{
PRIVATE:
Int N;
Double ** A, ** L, ** U;
Public:
Lluu (int nn)
{
Int I;
N = nn;
A = new double * [N];
For (I = 0; I <n; I ++) A [I] = new double [n + 8];
L = new double * [N];
For (I = 0; I <n; I ++) L [I] = new double [n + 8];
U = new double * [N];
For (I = 0; I <n; I ++) U [I] = new double [n + 8];
}
Void input ();
Void Lu ();
Void output ();
~ Lluu ()
{
Int I;
For (I = 0; I <n; I ++) {Delete [] a [I];}
Delete [];
For (I = 0; I <n; I ++) {Delete [] L [I];}
Delete [] L;
For (I = 0; I <n; I ++) {Delete [] U [I];}
Delete [] U;
}
};

Void lluu: input ()
{
Int I, J;
Char str1 [20];
Cout <"input file name :";
Cin> str1;
Ifstream fin (str1 );
If (! Fin)
{Cout <"\ n cannot open this file" <str1 <Endl; exit (1 );}
For (I = 0; I <n; I ++)
For (j = 0; j <n; j ++)
Fin> A [I] [J];
Fin. Close ();
}

Void lluu: Lu ()
{
Int I, J, K;
For (k = 0; k <n-1; k ++)
{
For (I = k + 1; I <n; I ++)
{
A [I] [k] = A [I] [k]/A [k] [k];
For (j = k + 1; j <n; j ++)
A [I] [J] = A [I] [J]-A [I] [k] * A [k] [J];
}
}
For (I = 0; I <n; I ++)
{
For (j = 0; j <n; j ++)
{
If (j <I) {L [I] [J] = A [I] [J]; U [I] [J] = 0 ;}
If (j = I) {L [I] [J] = 1; U [I] [J] = A [I] [J];}
If (j> I) {L [I] [J] = 0; U [I] [J] = A [I] [J];}
}
}
}

Void lluu: output ()
{
Int I, J;
Char str2 [20];
Cout <"output file name :";
Cin> str2;
Ofstream fout (str2 );
If (! Fout)
{Cout <"\ n cannot open this file" <str2 <Endl; exit (1 );}
For (I = 0; I <n; I ++)
{
For (j = 0; j <n; j ++)
{Fout <"<L [I] [J];
Cout <"<L [I] [J];
}
Fout <Endl; cout <Endl;
}
Fout <Endl; cout <Endl;
For (I = 0; I <n; I ++)
{
For (j = 0; j <n; j ++)
{Fout <"<u [I] [J];
Cout <"<u [I] [J];
}
Fout <Endl; cout <Endl;
}
Fout. Close ();
}

Int main ()
{
Lluu C (4 );
C. Input ();
C. Lu ();
C. Output ();
Return 0;
}