RosettaCodeData/Task/Amicable-pairs/Rust/amicable-pairs-2.rust

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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));
}
}
}