Source code in the rust programming language

fn sum_of_divisors(val: u32) -> u32 {
    (1..val/2+1).filter(|n| val % n == 0)
                .fold(0, |sum, n| sum + n)
}

fn main() {
    let iter = (1..20_000).map(|i| (i, sum_of_divisors(i)))
                          .filter(|&(i, div_sum)| i > div_sum);

    for (i, sum1) in iter {
        if sum_of_divisors(sum1) == i {
           println!("{} {}", i, sum1);
        }
    }
}


fn main() {
    const RANGE_MAX: u32 = 20_000;
    
    let proper_divs = |n: u32| -> Vec<u32> {
        (1..=(n + 1) / 2).filter(|&x| n % x == 0).collect()
    };
    
    let n2d: Vec<u32> = (1..=RANGE_MAX).map(|n| proper_divs(n).iter().sum()).collect();
    
    for (n, &div_sum) in n2d.iter().enumerate() {
        let n = n as u32 + 1;
        
        if n < div_sum && div_sum <= RANGE_MAX && n2d[div_sum as usize - 1] == n {
            println!("Amicable pair: {} and {} with proper divisors:", n, div_sum);
            println!("    {:?}", proper_divs(n));
            println!("    {:?}", proper_divs(div_sum));
        }
    }
}