rust lang book practice collections

main.rs

use std::collections::HashMap;
use std::cmp::Ordering;

fn gen_mean(input: &Vec<u32>) -> String {
    let sum = input.iter().fold(0, |acc, x| acc + x);
    
    return (sum as usize / input.len()).to_string();
}

fn gen_median(input: &Vec<u32>) -> String {
    let is_odd = input.len() % 2 == 1;
    let mut input = input.to_vec();
    input.sort_unstable();
    
    let input_len = input.len();
    let input_len_half = input_len / 2;
    
    match is_odd {
        true => {
            input[input_len_half + 1].to_string()
        },
        false => {
            ((input[input_len_half] + input[input_len_half + 1]) / 2)
                .to_string()
        },
    }
}

fn gen_middle(input: &Vec<u32>) -> String {
    input[input.len() / 2 as usize].to_string()
}

fn gen_mode(input: &Vec<u32>) -> String {
    let mut occurrences = HashMap::<u32, u32>::new();
    
    for &x in input.iter() {
        let counter = occurrences.entry(x).or_insert(0);
        *counter += 1;
    }
    
    let mut sorted: Vec<(&u32, &u32)> = occurrences.iter().collect();
    sorted.sort_by(|x, y| y.1.cmp(&x.1));
    
    sorted[0].0.to_string()
}

fn main() {
    let input = vec!(4, 8, 15, 16, 23, 42, 16, 23, 23);
    
    println!("{}", 11 as f32 / 2 as f32);
    
    println!(
        "mean: {}\nmedian: {}\nmiddle: {}\nmode: {}",
        gen_mean(&input),
        gen_median(&input),
        gen_middle(&input),
        gen_mode(&input)
    );
}