4) The following code is for Linear Algebra's Gaussian Elimination. A client with no technical background wants to know what is going on in this code. How would you explain this code line-for-line?

package GaussElim;

import java.util.Scanner;

public class GaussianElimination

{

public void solve(double[][] A, double[] B)

{

int N = B.length;

for (int k = 0; k < N; k++)

{

//find pivot row

int max = k;

for (int i = k + 1; i < N; i++)

if (Math.abs(A[i][k]) > Math.abs(A[max][k]))

max = i;

// swap row in A matrix

double[] temp = A[k];

A[k] = A[max];

A[max] = temp;

// swap corresponding values in constants matrix

double t = B[k];

B[k] = B[max];

B[max] = t;

// pivot within A and B

for (int i = k + 1; i < N; i++)

{

double factor = A[i][k] / A[k][k];

B[i] -= factor * B[k];

for (int j = k; j < N; j++)

A[i][j] -= factor * A[k][j];

}

}

// Print row echelon form

printRowEchelonForm(A, B);