fn main(){
let a = &[1, 2, 3];
for n in a.iter(){
println!("{}", n);
}
for (i, n) in a.iter().enumerate(){
println!("{}: {}", i, n);
}
for (i, n) in a.iter().skip(1).enumerate(){
println!("{}: {}", i, n);
}
let result : Vec<_> = a.iter().zip(a.iter().skip(1)).map(|(a, b)| a*b).collect();
println!("{:?}", result);
}