mirror of https://github.com/01-edu/public.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
1.1 KiB
57 lines
1.1 KiB
4 years ago
|
## matrix_determinant
|
||
|
|
|
||
|
|
### Instructions
|
||
|
|
|
||
|
|
Write a matrix_determinant function that receives a 3x3 matrix ([[isize; 3]; 3]) and returns its determinant (isize).
|
||
|
|
|
||
|
|
This is how you calculate a 2x2 matrix determinant:
|
||
|
|
|
||
|
|
```sh
|
||
|
|
|a b|
|
||
|
|
|c d|
|
||
|
|
|
||
|
|
a*d - b*c
|
||
|
|
```
|
||
|
|
|
||
|
|
To calculate a 3x3 matrix determinant (below) you have to take 'a' and multiply it by the determinant of the matrix you get if you get rid of 'a' column and row. Then you subtract the multiplication of 'b' and the determinant of the matrix you get if you get rid of 'b' column and row. And finally, you do the same process for 'c' and add it to the previous result.
|
||
|
|
|
||
|
|
```sh
|
||
|
|
|a b c|
|
||
|
|
|d e f|
|
||
|
|
|g h i|
|
||
|
|
```
|
||
|
|
|
||
|
|
### Expected Function
|
||
|
|
|
||
|
|
```rs
|
||
|
|
pub fn matrix_determinant(matrix: [[isize; 3]; 3]) -> isize {
|
||
|
|
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
### Example
|
||
|
|
|
||
|
|
Here is a program to test your function:
|
||
|
|
|
||
|
|
```rs
|
||
|
|
fn main() {
|
||
|
|
let matrix = [[1, 2, 4], [2, -1, 3], [4, 0, 1]];
|
||
|
|
|
||
|
|
println!(
|
||
|
|
"The determinant of the matrix:\n|1 2 4|\n|2 -1 3| = {}\n|4 0 1|",
|
||
|
|
matrix_determinant(matr)
|
||
|
|
);
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
And its output:
|
||
|
|
|
||
|
|
```sh
|
||
|
|
$ cargo run
|
||
|
|
The determinant of the matrix:
|
||
|
|
|1 2 4|
|
||
|
|
|2 -1 3| = 35
|
||
|
|
|4 0 1|
|
||
|
|
$
|
||
|
|
```
|