Getting transpose of matrix

Transpose a matrix

// Transpose a matrix
fn matrix_transpose(m: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
    let mut t = vec![Vec::with_capacity(m.len()); m[0].len()];
    for r in m {
        for i in 0..r.len() {
            t[i].push(r[i]);
        }
    }
    t
}

fn main() {
    let m = vec![vec![1, 2, 3], vec![4, 5, 6], vec![7, 8, 9]];
    println!("Matrix:\n{:?}", m);
    let t = matrix_transpose(m);
    println!("Transpose:\n{:?}", t);
}