projecteuler.net/049/main.rs

use std::collections::HashSet;

fn er() -> HashSet<u32> {
    let mut nums = Vec::new();
    let size = 9999;
    for n in 0..size+1 { nums.push(true); }
    let mut p = 1;
    loop {
        let mut found = false;
        for i in p+1..size {
            if nums[i] {
                found = true;
                p = i;
                break;
            }
        }
        if !found { break; }
        for i in (2 * p .. size).step_by(p) {
            nums[i] = false;
        }
    }
    let mut res = HashSet::new();
    for i in 2..size {
        if nums[i] { res.insert(i as u32); }
    }
    return res;
}

fn is_prms(a: u32, b: u32) -> bool {
    let aa = a.to_string();
    let bb = b.to_string();

    let mut hsa = HashSet::new();
    let mut hsb = HashSet::new();
    for c in aa.chars() {
        hsa.insert(c);
    }
    for c in bb.chars() {
        hsb.insert(c);
    }
    
    for _ in hsa.difference(&hsb) {
        return false;
    }
    return true;

}

fn main() {
    let hs = er();

    for p in hs.iter() {
        let p1 = *p;
        let p2 = p1 + 3330;
        let p3 = p2 + 3330;
        if hs.contains(&p1) && hs.contains(&p2) && hs.contains(&p3) {
            if is_prms(p1, p2) && is_prms(p2, p3) {
                println!("{} {} {}", p1, p2, p3);
            }
        } 
    }

    //let pp = is_prms(1487, 3300);
    //println!("{}", pp);

}