use std::ops::Range;
fn gav(x: i32, y: i32) -> i64 {
(x - y) * (x + y)
}
fn main() {
let num = 5;
let a = vec![1, 2, 3];
let b = Some(2);
let c = None;
let d = Range { start: 1, end: num };
let e = 1..num;
let f = "sssss".to_string();
for a in d {
for b in e {
let c = gav(gav(a, b), a);
assert_eq!(gav(a, b), a * a - b * b);
}
}
let f = d
.reduce(|a, b| {
println!("{}", a);
a * b
})
.unwrap();
}