rust

use std::collections::HashMap;
use std::path::PathBuf;

use walkdir::WalkDir;

pub fn group_by_size(root: &str) -> HashMap<u64, Vec<PathBuf>> {

use std::collections::HashMap;

fn main() {
    let mut scores = HashMap::new();
    scores.insert("Alice", 10);
    scores.insert("Bob", 20);

use std::fs;
use std::num::ParseIntError;

fn read_port(path: &str) -> Result<u16, Box<dyn std::error::Error>> {
    let contents = fs::read_to_string(path)?;
    let port: u16 = contents.trim().parse()?;

use serde::Deserialize;
use std::fmt;

#[derive(Debug, Deserialize)]
pub struct UserRecord {
    pub name: String,

use std::collections::HashMap;
use std::sync::Mutex;

pub type AccountId = u64;
pub type Cents = i64;

use std::fs;
use std::path::Path;

#[derive(Debug, Clone)]
pub struct Migration {
    pub version: i64,

use serde::Serialize;
use serde_json::Value;

#[derive(Debug, Clone, Serialize)]
#[serde(tag = "kind", rename_all = "lowercase")]
pub enum ChangeKind {

use std::fs;
use std::io::Result;

fn main() -> Result<()> {
    let contents = fs::read_to_string("input.txt")?;
    println!("File contents: {}", contents);

use std::fmt;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum OrderState {
    Pending,
    Paid,

use std::io::{self, Read, Write};

pub const HEADER_LEN: usize = 8; // 4-byte length + 4-byte crc

#[derive(Debug)]
pub enum DecodeError {

use std::fs::File;
use std::io::{BufRead, BufReader, Result};

fn main() -> Result<()> {
    let file = File::open("input.txt")?;
    let reader = BufReader::new(file);

fn greet(name: &str) {
    println!("Hello, {}", name);
}

fn main() {
    let owned = String::from("Alice");