HOW TO FIND INVERSE OF A MATRIX USING C++?

INVERSE OF A MATRIX

This post is for CLASS 12 Students. Are you bored to find Determinant, Cofactor, Adjoint and Finally Inverse ?

What if you type the question and all the above things come directly on your computer screen.

First I will say how did i do this?

•     Know the normal way
•     Find the shortcut. Here I used a Shortcut.
•     Write down Algorithm.
•     Now Start Coding.
•     You should be focussed on your output.
•     Combine Maths and C++
•     That's it. You did it.

Here is a sample.

Or what if Determinant is ZERO.Check this

What NEXT?..........CODE. Copy and paste it in your Notepad and change it into .cpp. Here is the code.

1. #include<iostream.h>
2. #include<conio.h>
3. void get(int a[3][3])
4. {
5.  for(int i=0;i<3;i++)
6.  {
7.   for(int j=0;j<3;j++)
8.   {
9.    cout<<"Enter the value of...a["<<i+1<<"]["<<j+1<<"]....";
10.    cin>>a[i][j];
11.   }
12.  }
13. }
14. void disp(int d[3][3])
15. {
16.  cout<<"\n";
17.  for(int i=0;i<3;i++)
18.  {
19.   for(int j=0;j<3;j++)
20.   {
21.    cout<<"\t"<<d[i][j];
22.   }
23.   cout<<"\n";
24.  }
25. }
26. int det(int a[3][3])
27. {
28. int mod;
29. mod=(a[0][0]*(a[1][1]*a[2][2]-a[2][1]*a[1][2]))-(a[0][1]*(a[1][0]*a[2][2]-a[2][0]*a[1][2]))+(a[0][2]*(a[1][0]*a[2][1]-a[2][0]*a[1][1]));
30. cout<<"\nDeterminant of A="<<mod;
31. return mod;
32. }
33. void main()
34. {
35. clrscr();
36. int a[3][3],mod,adj[3][3],co[3][3];
37. get(a);
38. disp(a);
39. mod=det(a);
40. cout<<"\nA Inverse is (1/Determinant of A)*Adjoint A";
41.  if(mod==0)
42.  {
43.  cout<<"\nInverse doesnt exist.";
44.  }
45.  else
46.  {
47.  co[0][0]=a[1][1]*a[2][2]-a[2][1]*a[1][2];
48.  co[0][1]=a[1][2]*a[2][0]-a[2][2]*a[1][0];
49.  co[0][2]=a[1][0]*a[2][1]-a[2][0]*a[1][1];
50.  co[1][0]=a[2][1]*a[0][2]-a[0][1]*a[2][2];
51.  co[1][1]=a[2][2]*a[0][0]-a[0][2]*a[2][0];
52.  co[1][2]=a[2][0]*a[0][1]-a[0][0]*a[2][1];
53.  co[2][0]=a[0][1]*a[1][2]-a[1][1]*a[0][2];
54.  co[2][1]=a[0][2]*a[1][0]-a[1][2]*a[0][0];
55.  co[2][2]=a[0][0]*a[1][1]-a[1][0]*a[0][1];
56.  cout<<"\nCofactor matrix...";
57.  disp(co);
58.  adj[0][0]=a[1][1]*a[2][2]-a[2][1]*a[1][2];
59.  adj[1][0]=a[1][2]*a[2][0]-a[2][2]*a[1][0];
60.  adj[2][0]=a[1][0]*a[2][1]-a[2][0]*a[1][1];
61.  adj[0][1]=a[2][1]*a[0][2]-a[0][1]*a[2][2];
62.  adj[1][1]=a[2][2]*a[0][0]-a[0][2]*a[2][0];
63.  adj[2][1]=a[2][0]*a[0][1]-a[0][0]*a[2][1];
64.  adj[0][2]=a[0][1]*a[1][2]-a[1][1]*a[0][2];
65.  adj[1][2]=a[0][2]*a[1][0]-a[1][2]*a[0][0];
66.  adj[2][2]=a[0][0]*a[1][1]-a[1][0]*a[0][1];
67.  cout<<"\nAdjoint matrix...";
68.  disp(adj);
69.  }
70. getch();
71. } 

Now its your turn.Try making a code for 2x2 matrix.If you succeed comment below.

YOU can ask any other program like this in comments or you can  mail me.