fn print_matrix(matrix: &Vec<Vec<i32>>) {
for row in matrix {
for val in row {
// pad each number to width 4
print!("{:4}", val);
}
println!();
}
}
fn inverse_matrix(matrix: &mut Vec<Vec<i32>>) {
let rows = matrix.len();
let cols = matrix[0].len();
let mut counter = 0;
let mut r = rows - 1;
for i in 0..rows {
let mut c = cols - 1;
for j in 0..cols {
// swap values
let tmp = matrix[i][j];
matrix[i][j] = matrix[r][c];
matrix[r][c] = tmp;
counter += 1;
if counter > (rows * cols) / 2 - 1 {
return;
}
if c > 0 { c -= 1; }
}
if r > 0 { r -= 1; }
}
}
fn main() {
let mut matrix = vec![
vec![1, 2, 3, 4],
vec![5, 6, 7, 8],
vec![9, 10, 11, 12],
];
println!("matrix:");
print_matrix(&matrix);
inverse_matrix(&mut matrix);
println!("\ninverse matrix:");
print_matrix(&matrix);
}
/*
run:
matrix:
1 2 3 4
5 6 7 8
9 10 11 12
inverse matrix:
12 11 10 9
8 7 6 5
4 3 2 1
*/
