Thread: determinants

could some one point me to an algorithm to find the determinant of a square matrix, not using recursion?

Thanks

why not using recursion? i'm guessing this is homework

here's a few hints:

Code:

| 3 4 5 |
| 6 7 8 |
| 9 1 2 |

there are 2 ways to determine determinates by minors
or by diagonals

Code:

| 3 4 5 3 4 |
| 6 7 8 6 7 |
| 9 1 2 9 1 |

the last two columns are repeats

try this:
assuming a matrix is int a[3][3];, and its filled like above

Code:

#define BORDER_CONSTANT 3
int t=0, u=0;
for (i=0;i<3;i++)
   for (j=0;j<3;j++)
     t+=a[(i+j)%BORDER_CONSTANT][i];
for (i=2;i<=0;i--)
   for (j=0;j<3;j++)
     u+=a[(i+j)%BORDER_CONSTANT][i];
printf("%d",t-u);

i havent tested this or anything, but try to figure it out from this

>why not using recursion?

Since his/her assignment told him not to do.

thanks. Yeah its home work, although it didnt say it couldnt be recursion, I didnt want to make it recursion. Also, its not C/C++, some new language(to me). I just couldnt get my algorithm to work right. But thanks