// exru6.ru  create and use functions and procedures

fn factorial(i: u64) -> u64 {
    match i {
        0 => 1,
        n => n * factorial(n-1)
    }
} // end factorial

fn sort(n:usize, mut _a:Vec<f64>) -> Vec<f64>
{
  println!("sort n= {:?}",n);
  println!("a= {:?}",_a);
  let mut  b = vec![0.0_f64; n];
  for i in 0..n
  {
    b[i] = _a[i];
  }
  for i in 0..(n-1)
  {
    let mut k = i;
    for j in (i+1)..n
    {
      if b[j] < b[k]
      {
        k = j;
      }
      if k != i
      {
        let t = b[i];
        b[i] = b[k];
        b[k] = t;
      }
    }
  }
  return b;
} // end sort

fn main()
{
  println!("exru6.ru running");
  let result = factorial(10);
  println!("factorial(10)= {}",result);

  let n = 10;
  let mut  x = vec![0.0_f64; n];
  let mut xs = vec![0.0_f64; n];
  println!("sort vector of double, n= {}", n);
  for i in 0..n
  {
    x[i] = (n as f64)-(i as f64);
    print!("x[{}",i);
    println!("]= {:?}", x[i]);
  }
  xs = sort(n,x);
  println!("result vector");
  for i in 0..n
  {
    print!("xs[{}",i);
    println!("]= {:?}", xs[i]);
  }

  println!(" ");  
  println!("exru6.ru finished");
}