#include <conio.h>
#include <iostream.h>
#include <stdio.h>


int main()

{

     int A[3][3];// the matrix that is entered by user

     int B[3][3];//the taranahade of a matrix A

     int C[3][3];//the adjunct matrix of transpose of a matrix A not adjunct of A

     double X[3][3];//the inverse

     int i,j;

     float x;

     int n=0;//n is the determinant of a

     clrscr();

     printf("========== Enter matrix A =============================================\n");

     for(i=0;i<3;i++)

     {

     printf("\n");

	  for(j=0;j<3;j++)

	  {

	       printf("A[%d][%d]=",i,j);

	       scanf("%d",&A[i][j]);

	       B[i][j]=0;

	       C[i][j]=0;

	  }

     }


	  for(i=0,j=0;j<3;j++)

	  {

	       if(j==2)

	       n+=A[i][j]*A[i+1][0]*A[i+2][1];

	       else if(j==1)

	       n+=A[i][j]*A[i+1][j+1]*A[i+2][0];

	       else

	       n+=A[i][j]*A[i+1][j+1]*A[i+2][j+2];

	  }

	  for(i=2,j=0;j<3;j++)

	  {

	       if(j==2)

	       n-=A[i][j]*A[i-1][0]*A[i-2][1];

	       else if(j==1)

	       n-=A[i][j]*A[i-1][j+1]*A[i-2][0];

	       else

	       n-=A[i][j]*A[i-1][j+1]*A[i-2][j+2];

	  }


     printf("\n========== The matrix A is ==========================================\n");

     for(i=0;i<3;i++)

     {

	  printf("\n");

	  for(j=0;j<3;j++)

	  {

	       printf(" A[%d][%d]=%d  ",i,j,A[i][j]);

	  }

     }

     printf("\n\n");

     printf("=====================================================================\n\n");

     printf("The determinant of matrix A is %d\n\n",n);

     printf("=====================================================================\n");

     if(n!=0) x=1.0/n;

     else

     {

	  printf("Division by 0, not good!\n");

	  printf("=====================================================================\n\n");

	  getch();

	  return 0;

     }

     printf("\n========== The transpose of a matrix A ==============================\n");

     for(i=0;i<3;i++)

     {

	  printf("\n");

	  for(j=0;j<3;j++)

	  {


	       B[i][j]=A[j][i];

	       printf(" B[%d][%d]=%d   ",j,i,B[i][j]);


	  }

     }

     printf("\n\n");


     C[0][0]=B[1][1]*B[2][2]-(B[2][1]*B[1][2]);

     C[0][1]=(-1)*(B[1][0]*B[2][2]-(B[2][0]*B[1][2]));

     C[0][2]=B[1][0]*B[2][1]-(B[2][0]*B[1][1]);


     C[1][0]=(-1)*(B[0][1]*B[2][2]-B[2][1]*B[0][2]);

     C[1][1]=B[0][0]*B[2][2]-B[2][0]*B[0][2];

     C[1][2]=(-1)*(B[0][0]*B[2][1]-B[2][0]*B[0][1]);


     C[2][0]=B[0][1]*B[1][2]-B[1][1]*B[0][2];

     C[2][1]=(-1)*(B[0][0]*B[1][2]-B[1][0]*B[0][2]);

     C[2][2]=B[0][0]*B[1][1]-B[1][0]*B[0][1];

     printf("\n========== The adjunct matrix of transpose of the matrix A ==========\n");

     for(i=0;i<3;i++)

     {

	  printf("\n");

	  for(j=0;j<3;j++)

	  {

	       printf(" C[%d][%d]=%d  ",i,j,C[i][j]);


	  }

     }

     printf("\n\n");


     for(i=0;i<3;i++)

     {

	  for(j=0;j<3;j++)

	  {

	       X[i][j]=C[i][j]*x;


	  }

     }


     printf("\n========== The inverse matrix of the matrix you entered!!! ==========\n");

     for(i=0;i<3;i++)

     {

	printf("\n");

	  for(j=0;j<3;j++)

	  {

	       printf(" X[%d][%d]=%f    ",i,j,X[i][j]);


	  }

     }

     printf("\n\n");

getch();

return 0;

}