#include <iostream>
#include <cmath>

using namespace std;
void print44(double A[4][4])
{

	for (int i=0;i<4;i++)

	{
		for (int j=0;j<4;j++)

		{

			cout<<A[i][j]<<"     ";


		}
		cout<<endl;

	}




}
double sumau (int i, int j, double A[4][4])

{
	double suma=0;
	for (int k=0;k<(i-1);k++)
	{

		suma=suma+A[i][k]+A[k][j];

	}
	return suma;


}


double sumal (int i, int j, double A[4][4])

{
	double suma=0;
	for (int k=0;k<(i-1);k++)
	{

		suma=suma+A[j][k]+A[k][i];

	}
	return suma;


}
int main ()

{

	double A[4][4]={{3,-4,4,-4},
					{1.5,-1,2,-2},
					{1.5,-0.5,0,-3},
					{4.5,-5.5,4,-9}};
	print44(A);
	double u[4][4];
	double l[4][4];
	for (int i=0; i<4;i++)
	{

		for (int j=0;j<4;j++)
		{
			if (i<=j) A[i][j]=A[i][j]-sumau(i,j,A);
			if (i<j) A[j][i]=(A[j][i]-sumal(i,j,A))/A[i][i];
		}



	}
	cout<<endl;
	print44(A);


	system("Pause");
	return 0;
}