day28.rs

use std::io;
use std::io::BufRead;

fn main() {
    let stdin = io::stdin();
    let lines: Vec<std::string::String> = stdin.lock().lines().map(|l| l.unwrap()).collect();
   
    let trimmed = lines[0].trim();
    let mut count = 0;
    
    match trimmed.parse::<usize>() {
        Ok(i) => count = i,
        Err(..) => println!("this was not an integer: {}", trimmed)
    };
    
    let contacts = (1..).take(count).map(|i| {
        let words: Vec<&str> = lines[i].trim().split_whitespace().collect();
        let (name, email) = (words[0], words[1]);
        
        (name, email)
    });

    let gmail_contacts = contacts.filter(|contact| contact.1.ends_with("@gmail.com"));
    let mut names = gmail_contacts.map(|contact| contact.0).collect::<Vec<&str>>();
    names.sort();
    
    for name in names {
        println!("{}", name);
    }
}