main.rs

use std::collections::HashMap;
use std::collections::BTreeMap;
use std::fs::File;
use std::io::prelude::*;
use std::str::FromStr;
use std::io::BufReader;

fn get_hm() -> HashMap<char, i16> {
    let file = BufReader::new(File::open("/tmp/scores.txt").unwrap());
    let mut hm = HashMap::new();
    for line in file.lines() {
        if let Ok(line) = line {
            let splitted: Vec<&str> = line.split_whitespace().collect();
            let alphabet = splitted[0].chars().next().unwrap();
            let number = i16::from_str(splitted[1]).unwrap();
            hm.insert(alphabet, number);
        }
    }
    hm
}


fn main() {
    let mut hm = get_hm();
    let mut line = String::new();
    let _ = std::io::stdin().read_line(&mut line);
    for ch in line.chars() {
        match hm.get_mut(&ch) {
            Some(count) => *count-=1,
            None => continue
        }
    }
    let mut count: BTreeMap<i16, Vec<char>> = BTreeMap::new();
    for (k,v) in hm {
        if v < 0 {
            println!("Invalid Input. More {}'s have been taken from the bag than possible.", k);
            std::process::exit(1);
        }
        count.insert(v, vec![k]);
    }
    for (k, v) in count.iter().rev() {
       print!("{}: ", k);
       for (idx, ch) in v.iter().enumerate() {
           if idx < v.len()-1 {
            print!("{},", ch);
           }
           else { println!("{}", ch); }
       }
    }
        
    
}