use std::collections::HashMap;

struct Pc {
    maker: String,
    year: u16,
}

fn main() {
    let my_mac = Pc {
        maker: "apple".to_string(),
        year: 2018,
    };
    let my_old_mac = Pc {
        maker: "apple".to_string(),
        year: 2016,
    };
    let my_old_old_mac = Pc {
        maker: "apple".to_string(),
        year: 2010,
    };
    let my_win = Pc {
        maker: "dell".to_string(),
        year: 2018,
    };
    let my_old_win = Pc {
        maker: "dell".to_string(),
        year: 2016,
    };
    let my_old_old_win = Pc {
        maker: "dell".to_string(),
        year: 2010,
    };

    let a = [
        my_mac,
        my_old_mac,
        my_old_old_mac,
        my_win,
        my_old_win,
        my_old_old_win,
    ];

    let mut counter: HashMap<&str, u16> = HashMap::new();
    counter.insert("apple", 0);
    counter.insert("dell", 0);

    let top_k = 3;
    let dedupe_num = 2;
    let iter = a
        .iter()
        .filter(|x| {
            *counter.get_mut::<str>(&x.maker).unwrap() += 1;
            *counter.get::<str>(&x.maker).unwrap() <= dedupe_num
        }).take(top_k);

    for it in iter {
        println!("{},{}", it.maker, it.year);
    }
}