package lastASSIGNMENT;

import java.io.File;
import java.util.Scanner;

class Main{
    public static void main(String[] args) {
        //Scanner scan = new Scanner(System.in);
        int i,j;
        Scanner scanner = new Scanner(System.in);


        System.out.println("Enter file location :");
        String file_name = scanner.nextLine();

        double mat[][] = new double[3][3];
        try{
            File f = new File(file_name);
            Scanner inp =  new Scanner(f);
            while(inp.hasNext()) {
        for( i =0;i<3;i++)
        {
            for( j=0;j<3;j++)
            {

                mat[i][j] =inp.nextInt();
            }
        }
            }
        }catch(Exception e) {

        }
        System.out.println("entered matrix ");
        for( i =0;i<3;i++)
        {
            for( j=0;j<3;j++)
            {
            	System.out.print(" "+mat[i][j]);
            }
            System.out.println("");
        }


        System.out.println("Inverse: ");
        Main.inverse(mat);



    }
  static   void inverse(double mat[][])
    {
        double adj[][] = new double[3][3];
        double matDet = 0;
        int i,j;
        for(i =0;i<3;i++)
        {
            if(i%2!=0)
            {
                matDet-=mat[0][i]*Main.det( Main.adjcent(mat,0,i,3));
            }
            else
            {
                matDet+=mat[0][i]*Main.det( Main.adjcent(mat,0,i,3));
            }
        }
        for( i =0;i<3;i++)
        {
            for( j=0;j<3;j++)
            {

                    if((i+j)%2!=0)
                adj[j][i]=Main.det( Main.adjcent(mat,i,j,3))*(1/matDet)*-1;
                    else
                        adj[j][i]=Main.det( Main.adjcent(mat,i,j,3))*(1/matDet);


            }
            System.out.println("\n");
        }
        for( i =0;i<3;i++)
        {
            for( j=0;j<3;j++)
            {

                System.out.print(adj[i][j]+" ");

            }
            System.out.println("\n");
        }

    }
   static double[][] adjcent(double arr[][],int r,int c,int n)
    {

        double brr[][] = new double[n-1][n-1];
        int x =0,y=0;
        for(int i=0;i<n;i++)
        {
            for(int j =0;j<n;j++)
            {
                if(i!=r && j!=c)
                {
                    brr[x][y]=arr[i][j];
                    if(y!=n-2)
                    {
                        y++;
                    }
                    else
                    {
                        x++;
                        y=0;

                    }

                }
            }
        }
        return brr;
    }
   static double det(double mat[][])
    {
       double det = (mat[0][0] * mat[1][1]) - (mat[0][1] * mat[1][0]);
    return  det;

    }

}