
My code:
import java.util.Scanner.*;
import java.util.*;
public class cramersrule
{
double A[][];
double m[][];
int N;
double B[];
public void input()
{
Scanner s=new Scanner(System.in);
System.out.println("enter no of equations of matrix");
N=s.nextInt();
A = new double[N][];
for(int i=0;i<N;i++)
{
A[i]=new double[N];
}
System.out.println("enter the co-efficient of equations");
for(int i=0;i<N;i++)
{
System.out.println("enter the co-efficient of of equation" + (i+1));
for(int j=0;j<N;j++)
{
double k=s.nextDouble();
A[i][j]=k;
}
}
B = new double[N];
System.out.println("enter the RHS of equations");
for(int i=0;i<N;i++)
{
System.out.println("enter the RHS of equations" + (i+1));
double k = s.nextDouble();
B[i] = k;
}
}
public double determinant(double A[][],int N)
{
double det=0;
double res;
if(N == 1)
res = A[0][0];
else if (N == 2)
{
res = A[0][0]*A[1][1] - A[1][0]*A[0][1];
}
else
{
res=0;
for(int j1=0;j1<N;j1++)
{
m = new double[N-1][];
for(int k=0;k<(N-1);k++)
m[k] = new double[N-1];
for(int i=1;i<N;i++)
{
int j2=0;
for(int j=0;j<N;j++)
{
if(j == j1)
continue;
m[i-1][j2] = A[i][j];
j2++;
}
}
res += Math.pow(-1.0,1.0+j1+1.0)* A[0][j1] * determinant(m,N-1);
}
}
return res;
}
public double[] cramers(double A[][],double B[])
{
double temp[][] = new double[N][N];
double x[] = new double[N];
for(int i=0;i<N;i++)
{
for(int j=0;j<N;j++){
for(int k=0;k<N;k++){
if(k == i)
temp[j][k] = B[j];
else
temp[j][k] = A[j][k];
}}
x[i]=determinant(temp,N)/determinant(A,N);
}
for(int i=0;i<N;i++){
System.out.println(x[i]);}
return x;
}
public static void main(String args[]){
double res;
cramersrule d = new cramersrule();
d.input();
d.cramers(d.A,d.B);
}
}
Thanks

import java.util.*;
public class cramersrule {
double A[][];
double m[][];
int N;
double B[];
public void input() {
Scanner s=new Scanner(System.in);
System.out.println("enter no of equations of matrix");
N=s.nextInt();
A = new double[N][];
for(int i=0;i<N;i++) {
A[i]=new double[N];
}
System.out.println("enter the co-efficient of equations");
for(int i=0;i<N;i++) {
System.out.println("enter the co-efficient of of equation" + (i+1));
for(int j=0;j<N;j++) {
double k=s.nextDouble();
A[i][j]=k;
}
}
B = new double[N];
System.out.println("enter the RHS of equations");
for(int i=0;i<N;i++){
System.out.println("enter the RHS of equations" + (i+1));
double k = s.nextDouble();
B[i] = k;
}
}
public double determinant(double A[][],int N) {
double det=0;
double res;
if(N == 1)
res = A[0][0];
else if(N == 2) {
res = (A[0][0]*A[1][1]) - (A[1][0]*A[0][1]);
}
else{
res=0;
for(int j1=0;j1<N;j1++) {
m = new double[N-1][];
for(int k=0;k<(N-1);k++)
m[k] = new double[N-1];
for(int i=1;i<N;i++) {
int j2=0;
for(int j=0;j<N;j++) {
if(j == j1)
continue;
m[i-1][j2] = A[i][j];
j2++;
}
}
res += Math.pow(-1.0,1.0+j1+1.0)* A[0][j1] * determinant(m,N-1);
}
}
return res;
}
public double[] cramers(double A[][],double B[]) {
double temp[][] = new double[N][N];
double x[] = new double[N];
for(int i=0;i<N;i++) {
for(int j=0;j<N;j++){
for(int k=0;k<N;k++){
if(k == i)
temp[j][k] = B[j];
else temp[j][k] = A[j][k];
}
}
x[i]=determinant(temp,N)/determinant(A,N);
}
for(int i=0;i<N;i++){
System.out.println(x[i]);
}
return x;
}
public static void main(String args[]){
double res;
cramersrule d = new cramersrule();
d.input();
d.cramers(d.A,d.B);
}
}