z-ai/glm-5.3-flash on Rust Quick Ten

Turn #1Raw score: 1

99 in1,291 out1,211 reasoning1,390 total15.6s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write is_palindrome(s: &str) -> bool. Consider only ASCII letters and digits, ignoring ASCII case and every other character. A string with none of those characters is a palindrome.

assistant

pub fn is_palindrome(s: &str) -> bool {
    let mut it = s.chars().filter(|c| c.is_ascii_alphanumeric());
    while let (Some(a), Some(b)) = (it.next(), it.next_back()) {
        if !a.eq_ignore_ascii_case(&b) {
            return false;
        }
    }
    true
}

Turn #2Raw score: 1

99 in1,252 out1,179 reasoning1,351 total22.6s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write is_palindrome(s: &str) -> bool. Consider only ASCII letters and digits, ignoring ASCII case and every other character. A string with none of those characters is a palindrome.

assistant

pub fn is_palindrome(s: &str) -> bool {
    let chars: Vec<u8> = s
        .bytes()
        .filter(|b| b.is_ascii_alphanumeric())
        .map(|b| b.to_ascii_lowercase())
        .collect();
    chars.iter().eq(chars.iter().rev())
}

Turn #3Raw score: 1

99 in1,301 out1,200 reasoning1,400 total22.2s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write is_palindrome(s: &str) -> bool. Consider only ASCII letters and digits, ignoring ASCII case and every other character. A string with none of those characters is a palindrome.

assistant

pub fn is_palindrome(s: &str) -> bool {
    let mut it = s
        .bytes()
        .filter(|b| b.is_ascii_alphanumeric())
        .map(|b| b.to_ascii_lowercase());

    while let Some(a) = it.next() {
        match it.next_back() {
            Some(b) if a != b => return false,
            Some(_) => {}
            None => break,
        }
    }
    true
}

Turn #4Raw score: 1

109 in322 out248 reasoning431 total3.1s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write word_count(text: &str) -> HashMap<String, usize>, importing HashMap yourself. Words are separated by any whitespace and compared in lowercase, and the map's keys are lowercase. Punctuation is part of a word.

assistant

use std::collections::HashMap;

fn word_count(text: &str) -> HashMap<String, usize> {
    let mut counts: HashMap<String, usize> = HashMap::new();
    for word in text.split_whitespace() {
        *counts.entry(word.to_lowercase()).or_insert(0) += 1;
    }
    counts
}

Turn #5Raw score: 1

109 in274 out199 reasoning383 total2.3s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write word_count(text: &str) -> HashMap<String, usize>, importing HashMap yourself. Words are separated by any whitespace and compared in lowercase, and the map's keys are lowercase. Punctuation is part of a word.

assistant

use std::collections::HashMap;

fn word_count(text: &str) -> HashMap<String, usize> {
    let mut counts: HashMap<String, usize> = HashMap::new();
    for word in text.split_whitespace() {
        *counts.entry(word.to_lowercase()).or_insert(0) += 1;
    }
    counts
}

Turn #6Raw score: 1

109 in224 out148 reasoning333 total2.5s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write word_count(text: &str) -> HashMap<String, usize>, importing HashMap yourself. Words are separated by any whitespace and compared in lowercase, and the map's keys are lowercase. Punctuation is part of a word.

assistant

use std::collections::HashMap;

fn word_count(text: &str) -> HashMap<String, usize> {
    let mut counts: HashMap<String, usize> = HashMap::new();
    for word in text.split_whitespace() {
        *counts.entry(word.to_lowercase()).or_insert(0) += 1;
    }
    counts
}

Turn #7Raw score: 1

106 in347 out295 reasoning453 total2.7s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write longest, which takes two string slices and returns the longer one by str::len without allocating. On a tie, it returns the first. Its result must be usable as long as both inputs are alive.

assistant

fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
    if x.len() >= y.len() {
        x
    } else {
        y
    }
}

Turn #8Raw score: 1

106 in211 out160 reasoning317 total2.6s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write longest, which takes two string slices and returns the longer one by str::len without allocating. On a tie, it returns the first. Its result must be usable as long as both inputs are alive.

assistant

fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
    if x.len() >= y.len() {
        x
    } else {
        y
    }
}

Turn #9Raw score: 1

106 in226 out175 reasoning332 total1.5s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write longest, which takes two string slices and returns the longer one by str::len without allocating. On a tie, it returns the first. Its result must be usable as long as both inputs are alive.

assistant

fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
    if x.len() >= y.len() {
        x
    } else {
        y
    }
}

Turn #10Raw score: 1

166 in786 out718 reasoning952 total6.0s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)>, importing FromStr yourself. Split s at the first occurrence of sep and parse both sides as T. Return None if sep does not occur or if either side fails to parse. sep may be any Unicode character. parse_pair::<u32>("400x600", 'x') returns Some((400, 600)).

assistant

use std::str::FromStr;

fn parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)> {
    let (left, right) = s.split_once(sep)?;
    Some((left.parse().ok()?, right.parse().ok()?))
}

Turn #11Raw score: 1

166 in667 out596 reasoning833 total4.3s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)>, importing FromStr yourself. Split s at the first occurrence of sep and parse both sides as T. Return None if sep does not occur or if either side fails to parse. sep may be any Unicode character. parse_pair::<u32>("400x600", 'x') returns Some((400, 600)).

assistant

use std::str::FromStr;

fn parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)> {
    let (left, right) = s.split_once(sep)?;
    Some((left.parse().ok()?, right.parse().ok()?))
}

Turn #12Raw score: 1

166 in633 out558 reasoning64 cached799 total4.8s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)>, importing FromStr yourself. Split s at the first occurrence of sep and parse both sides as T. Return None if sep does not occur or if either side fails to parse. sep may be any Unicode character. parse_pair::<u32>("400x600", 'x') returns Some((400, 600)).

assistant

use std::str::FromStr;

fn parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)> {
    let (left, right) = s.split_once(sep)?;
    Some((T::from_str(left).ok()?, T::from_str(right).ok()?))
}

Turn #13Raw score: 1

127 in499 out432 reasoning626 total18.3s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write compose(f, g), generic over the argument and result types. f and g are closures implementing Fn. It returns a closure implementing Fn that maps x to g(f(x)), and the returned closure must be usable after the function that called compose has returned.

assistant

fn compose<A, B, C, F, G>(f: F, g: G) -> impl Fn(A) -> C
where
    F: Fn(A) -> B,
    G: Fn(B) -> C,
{
    move |x| g(f(x))
}

Turn #14Raw score: 1

127 in2,399 out2,334 reasoning2,526 total23.9s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write compose(f, g), generic over the argument and result types. f and g are closures implementing Fn. It returns a closure implementing Fn that maps x to g(f(x)), and the returned closure must be usable after the function that called compose has returned.

assistant

fn compose<A, B, C, F, G>(f: F, g: G) -> impl Fn(A) -> C
where
    F: Fn(A) -> B,
    G: Fn(B) -> C,
{
    move |x| g(f(x))
}

Turn #15Raw score: 1

127 in7,488 out7,421 reasoning7,615 total70.7s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write compose(f, g), generic over the argument and result types. f and g are closures implementing Fn. It returns a closure implementing Fn that maps x to g(f(x)), and the returned closure must be usable after the function that called compose has returned.

assistant

fn compose<A, B, C, F, G>(f: F, g: G) -> impl Fn(A) -> C
where
    F: Fn(A) -> B,
    G: Fn(B) -> C,
{
    move |x| g(f(x))
}

Turn #16Raw score: 0

142 in6,079 out5,966 reasoning6,221 total55.0s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define Fib, with a constructor Fib::new(), and implement Iterator<Item = u64> for it. It yields the Fibonacci numbers 0, 1, 1, 2, 3, 5, and so on. It yields every Fibonacci number that fits in a u64, then None from then on. Tests run with overflow checks on.

assistant

pub struct Fib {
    prev: u64,
    curr: u64,
}

impl Fib {
    pub fn new() -> Self {
        Fib { prev: 1, curr: 0 }
    }
}

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<u64> {
        let item = self.curr;
        let next = self.prev.checked_add(self.curr)?;
        self.prev = self.curr;
        self.curr = next;
        Some(item)
    }
}

Turn #17Raw score: 0

142 in1,546 out1,434 reasoning64 cached1,688 total11.5s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define Fib, with a constructor Fib::new(), and implement Iterator<Item = u64> for it. It yields the Fibonacci numbers 0, 1, 1, 2, 3, 5, and so on. It yields every Fibonacci number that fits in a u64, then None from then on. Tests run with overflow checks on.

assistant

pub struct Fib {
    state: Option<(u64, u64)>,
}

impl Fib {
    pub fn new() -> Self {
        Fib { state: Some((0, 1)) }
    }
}

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<u64> {
        let (a, b) = self.state?;
        self.state = b.checked_add(a).map(|sum| (b, sum));
        Some(a)
    }
}

Turn #18Raw score: 1

142 in11,978 out11,857 reasoning64 cached12,120 total80.4s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define Fib, with a constructor Fib::new(), and implement Iterator<Item = u64> for it. It yields the Fibonacci numbers 0, 1, 1, 2, 3, 5, and so on. It yields every Fibonacci number that fits in a u64, then None from then on. Tests run with overflow checks on.

assistant

pub struct Fib {
    state: Option<(u64, u64)>,
}

impl Fib {
    pub fn new() -> Self {
        Fib {
            state: Some((1, 0)),
        }
    }
}

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<u64> {
        let (prev, curr) = self.state.take()?;
        if let Some(next) = prev.checked_add(curr) {
            self.state = Some((curr, next));
        }
        Some(curr)
    }
}

Turn #19Raw score: 1

243 in1,759 out1,393 reasoning2,002 total10.0s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define enum TempError deriving Debug, with the variants Empty, BadUnit(char), and BadNumber(std::num::ParseFloatError), and write parse_temp(s: &str) -> Result<f64, TempError>. The input is a number followed by one unit character, C or F, and the result is in Celsius, so "212F" returns 100.0. An empty string gives Empty. If the last character is neither C nor F, it gives BadUnit with that character, which may be non-ASCII. A number that does not parse gives BadNumber. Implement Display and std::error::Error for TempError, with source() returning the parse error for BadNumber, and implement From<std::num::ParseFloatError> for it.

assistant

use std::error::Error;
use std::fmt::{self, Display, Formatter};
use std::num::ParseFloatError;

#[derive(Debug)]
pub enum TempError {
    Empty,
    BadUnit(char),
    BadNumber(ParseFloatError),
}

impl Display for TempError {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            TempError::Empty => write!(f, "empty temperature string"),
            TempError::BadUnit(c) => write!(f, "invalid unit character: {c}"),
            TempError::BadNumber(e) => write!(f, "invalid number: {e}"),
        }
    }
}

impl Error for TempError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            TempError::BadNumber(e) => Some(e),
            TempError::Empty | TempError::BadUnit(_) => None,
        }
    }
}

impl From<ParseFloatError> for TempError {
    fn from(e: ParseFloatError) -> Self {
        TempError::BadNumber(e)
    }
}

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    let Some(last) = s.chars().next_back() else {
        return Err(TempError::Empty);
    };
    let (num, unit) = s.split_at(s.len() - last.len_utf8());
    let value: f64 = num.parse()?;
    match unit {
        "C" => Ok(value),
        "F" => Ok((value - 32.0) * 5.0 / 9.0),
        _ => Err(TempError::BadUnit(last)),
    }
}

Turn #20Raw score: 1

243 in1,491 out1,134 reasoning128 cached1,734 total9.8s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define enum TempError deriving Debug, with the variants Empty, BadUnit(char), and BadNumber(std::num::ParseFloatError), and write parse_temp(s: &str) -> Result<f64, TempError>. The input is a number followed by one unit character, C or F, and the result is in Celsius, so "212F" returns 100.0. An empty string gives Empty. If the last character is neither C nor F, it gives BadUnit with that character, which may be non-ASCII. A number that does not parse gives BadNumber. Implement Display and std::error::Error for TempError, with source() returning the parse error for BadNumber, and implement From<std::num::ParseFloatError> for it.

assistant

use std::error::Error;
use std::fmt;
use std::num::ParseFloatError;

#[derive(Debug)]
pub enum TempError {
    Empty,
    BadUnit(char),
    BadNumber(ParseFloatError),
}

impl fmt::Display for TempError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            TempError::Empty => write!(f, "empty input"),
            TempError::BadUnit(c) => write!(f, "bad unit character: {c}"),
            TempError::BadNumber(e) => write!(f, "bad number: {e}"),
        }
    }
}

impl Error for TempError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            TempError::BadNumber(e) => Some(e),
            _ => None,
        }
    }
}

impl From<ParseFloatError> for TempError {
    fn from(e: ParseFloatError) -> Self {
        TempError::BadNumber(e)
    }
}

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    let unit = s.chars().last().ok_or(TempError::Empty)?;
    if unit != 'C' && unit != 'F' {
        return Err(TempError::BadUnit(unit));
    }
    let num_part = &s[..s.len() - unit.len_utf8()];
    let value: f64 = num_part.parse()?;
    Ok(if unit == 'F' {
        (value - 32.0) * 5.0 / 9.0
    } else {
        value
    })
}

Turn #21Raw score: 1

243 in2,228 out1,875 reasoning128 cached2,471 total12.8s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define enum TempError deriving Debug, with the variants Empty, BadUnit(char), and BadNumber(std::num::ParseFloatError), and write parse_temp(s: &str) -> Result<f64, TempError>. The input is a number followed by one unit character, C or F, and the result is in Celsius, so "212F" returns 100.0. An empty string gives Empty. If the last character is neither C nor F, it gives BadUnit with that character, which may be non-ASCII. A number that does not parse gives BadNumber. Implement Display and std::error::Error for TempError, with source() returning the parse error for BadNumber, and implement From<std::num::ParseFloatError> for it.

assistant

use std::error::Error;
use std::fmt;
use std::num::ParseFloatError;

#[derive(Debug)]
pub enum TempError {
    Empty,
    BadUnit(char),
    BadNumber(ParseFloatError),
}

impl fmt::Display for TempError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            TempError::Empty => write!(f, "empty input"),
            TempError::BadUnit(c) => write!(f, "bad unit character: {c}"),
            TempError::BadNumber(e) => write!(f, "bad number: {e}"),
        }
    }
}

impl Error for TempError {
    fn source(&self) -> Option<&(dyn Error + 'static)> {
        match self {
            TempError::BadNumber(e) => Some(e),
            _ => None,
        }
    }
}

impl From<ParseFloatError> for TempError {
    fn from(e: ParseFloatError) -> Self {
        TempError::BadNumber(e)
    }
}

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    let mut chars = s.chars();
    let unit = chars.next_back().ok_or(TempError::Empty)?;
    if unit != 'C' && unit != 'F' {
        return Err(TempError::BadUnit(unit));
    }
    let number: String = chars.collect();
    let value: f64 = number.parse()?;
    Ok(match unit {
        'F' => (value - 32.0) * 5.0 / 9.0,
        _ => value,
    })
}

Turn #22Raw score: 1

144 in2,035 out1,873 reasoning2,179 total13.5s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parallel_sum(data: &[u64], workers: usize) -> u64, which sums data by splitting it across workers threads from std::thread. data is a borrowed slice, and workers may be larger than data.len(). It returns 0 for an empty slice and panics when workers is 0, including when the slice is empty.

assistant

use std::thread;

pub fn parallel_sum(data: &[u64], workers: usize) -> u64 {
    assert!(workers > 0, "workers must be greater than zero");

    if data.is_empty() {
        return 0;
    }

    let workers = workers.min(data.len());
    let chunk_size = data.len().div_ceil(workers);

    thread::scope(|scope| {
        let handles: Vec<_> = data
            .chunks(chunk_size)
            .map(|chunk| scope.spawn(move || chunk.iter().sum::<u64>()))
            .collect();

        handles
            .into_iter()
            .map(|handle| handle.join().expect("worker thread panicked"))
            .sum::<u64>()
    })
}

Turn #23Raw score: 1

144 in8,161 out7,954 reasoning64 cached8,305 total50.6s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parallel_sum(data: &[u64], workers: usize) -> u64, which sums data by splitting it across workers threads from std::thread. data is a borrowed slice, and workers may be larger than data.len(). It returns 0 for an empty slice and panics when workers is 0, including when the slice is empty.

assistant

use std::thread;

pub fn parallel_sum(data: &[u64], workers: usize) -> u64 {
    assert!(workers > 0, "workers must be greater than zero");

    if data.is_empty() {
        return 0;
    }

    let len = data.len();
    let thread_count = workers.min(len);
    let base = len / thread_count;
    let remainder = len % thread_count;
    let offset = |i: usize| i * base + i.min(remainder);

    thread::scope(|scope| {
        let handles: Vec<_> = (0..thread_count)
            .map(|i| {
                let chunk = &data[offset(i)..offset(i + 1)];
                scope.spawn(move || chunk.iter().sum::<u64>())
            })
            .collect();

        handles
            .into_iter()
            .map(|handle| handle.join().expect("worker thread panicked"))
            .sum::<u64>()
    })
}

Turn #24Raw score: 1

144 in6,063 out5,911 reasoning64 cached6,207 total36.9s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Write parallel_sum(data: &[u64], workers: usize) -> u64, which sums data by splitting it across workers threads from std::thread. data is a borrowed slice, and workers may be larger than data.len(). It returns 0 for an empty slice and panics when workers is 0, including when the slice is empty.

assistant

use std::thread;

pub fn parallel_sum(data: &[u64], workers: usize) -> u64 {
    assert!(workers > 0, "workers must be greater than zero");

    if data.is_empty() {
        return 0;
    }

    thread::scope(|scope| {
        let chunk_size = data.len().div_ceil(workers);

        let handles: Vec<_> = data
            .chunks(chunk_size)
            .map(|chunk| scope.spawn(move || chunk.iter().sum::<u64>()))
            .collect();

        handles
            .into_iter()
            .map(|handle| handle.join().expect("worker thread panicked"))
            .sum::<u64>()
    })
}

Turn #25Raw score: 1

134 in10,222 out9,805 reasoning10,356 total60.7s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define an extension trait PairsExt that adds a method .pairs() to every iterator whose items implement Clone. It returns a lazy iterator of consecutive overlapping pairs, so (1..4).pairs() yields (1, 2) then (2, 3). A source with fewer than two items yields nothing, and an infinite source must work.

assistant

use std::iter::FusedIterator;

pub trait PairsExt: Iterator {
    fn pairs(self) -> Pairs<Self>
    where
        Self: Sized,
        Self::Item: Clone,
    {
        Pairs {
            iter: self,
            prev: None,
        }
    }
}

impl<I: Iterator> PairsExt for I {}

pub struct Pairs<I>
where
    I: Iterator,
    I::Item: Clone,
{
    iter: I,
    prev: Option<I::Item>,
}

impl<I> Iterator for Pairs<I>
where
    I: Iterator,
    I::Item: Clone,
{
    type Item = (I::Item, I::Item);

    fn next(&mut self) -> Option<Self::Item> {
        loop {
            let item = self.iter.next()?;
            match self.prev.take() {
                Some(prev) => {
                    self.prev = Some(item.clone());
                    return Some((prev, item));
                }
                None => self.prev = Some(item),
            }
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let (lo, hi) = self.iter.size_hint();
        let held = usize::from(self.prev.is_some());
        let lower = if lo == 0 { 0 } else { lo - 1 + held };
        let upper = hi.map(|h| if h == 0 { 0 } else { (h - 1).saturating_add(held) });
        (lower, upper)
    }
}

impl<I> FusedIterator for Pairs<I>
where
    I: Iterator + FusedIterator,
    I::Item: Clone,
{
}

impl<I> Clone for Pairs<I>
where
    I: Iterator + Clone,
    I::Item: Clone,
{
    fn clone(&self) -> Self {
        Self {
            iter: self.iter.clone(),
            prev: self.prev.clone(),
        }
    }
}

Turn #26Raw score: 0

134 in12,714 out12,325 reasoning64 cached12,848 total79.0s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define an extension trait PairsExt that adds a method .pairs() to every iterator whose items implement Clone. It returns a lazy iterator of consecutive overlapping pairs, so (1..4).pairs() yields (1, 2) then (2, 3). A source with fewer than two items yields nothing, and an infinite source must work.

assistant

use std::iter::{ExactSizeIterator, FusedIterator};

pub struct Pairs<I> {
    iter: I,
    prev: Option<I::Item>,
}

impl<I> Iterator for Pairs<I>
where
    I: Iterator,
    I::Item: Clone,
{
    type Item = (I::Item, I::Item);

    fn next(&mut self) -> Option<Self::Item> {
        let first = match self.prev.take() {
            Some(item) => item,
            None => self.iter.next()?,
        };
        let second = self.iter.next()?;
        self.prev = Some(second.clone());
        Some((first, second))
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let (lower, upper) = self.iter.size_hint();
        if self.prev.is_some() {
            (lower, upper)
        } else {
            (
                lower.saturating_sub(1),
                upper.map(|upper| upper.saturating_sub(1)),
            )
        }
    }
}

impl<I> FusedIterator for Pairs<I>
where
    I: FusedIterator,
    I::Item: Clone,
{
}

impl<I> ExactSizeIterator for Pairs<I>
where
    I: ExactSizeIterator,
    I::Item: Clone,
{
    fn len(&self) -> usize {
        let len = self.iter.len();
        if self.prev.is_some() {
            len
        } else {
            len.saturating_sub(1)
        }
    }
}

pub trait PairsExt: Iterator {
    fn pairs(self) -> Pairs<Self>
    where
        Self: Sized,
        Self::Item: Clone,
    {
        Pairs {
            iter: self,
            prev: None,
        }
    }
}

impl<I: Iterator> PairsExt for I {}

Turn #27Raw score: 1

134 in14,897 out14,408 reasoning64 cached15,031 total91.3s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define an extension trait PairsExt that adds a method .pairs() to every iterator whose items implement Clone. It returns a lazy iterator of consecutive overlapping pairs, so (1..4).pairs() yields (1, 2) then (2, 3). A source with fewer than two items yields nothing, and an infinite source must work.

assistant

use std::iter::FusedIterator;

pub trait PairsExt: Iterator {
    fn pairs(self) -> Pairs<Self>
    where
        Self: Sized,
        Self::Item: Clone;
}

impl<I: Iterator> PairsExt for I {
    fn pairs(self) -> Pairs<Self>
    where
        Self: Sized,
        Self::Item: Clone,
    {
        Pairs {
            iter: self,
            prev: None,
            done: false,
        }
    }
}

pub struct Pairs<I: Iterator> {
    iter: I,
    prev: Option<I::Item>,
    done: bool,
}

impl<I> Iterator for Pairs<I>
where
    I: Iterator,
    I::Item: Clone,
{
    type Item = (I::Item, I::Item);

    fn next(&mut self) -> Option<Self::Item> {
        if self.done {
            return None;
        }
        let prev = match self.prev.take() {
            Some(prev) => prev,
            None => match self.iter.next() {
                Some(first) => first,
                None => {
                    self.done = true;
                    return None;
                }
            },
        };
        match self.iter.next() {
            Some(current) => {
                self.prev = Some(current.clone());
                Some((prev, current))
            }
            None => {
                self.done = true;
                None
            }
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        if self.done {
            return (0, Some(0));
        }
        let (lower, upper) = self.iter.size_hint();
        if self.prev.is_some() {
            (lower, upper)
        } else {
            (
                lower.saturating_sub(1),
                upper.map(|u| u.saturating_sub(1)),
            )
        }
    }
}

impl<I> FusedIterator for Pairs<I>
where
    I: Iterator,
    I::Item: Clone,
{
}

impl<I> Clone for Pairs<I>
where
    I: Iterator + Clone,
    I::Item: Clone,
{
    fn clone(&self) -> Self {
        Pairs {
            iter: self.iter.clone(),
            prev: self.prev.clone(),
            done: self.done,
        }
    }
}

Turn #28Raw score: 1

189 in1,128 out887 reasoning1,317 total7.1s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define TreeNode with exactly these fields: value: i32, parent: RefCell<Weak<TreeNode>>, and children: RefCell<Vec<Rc<TreeNode>>>, importing those types from the standard library. Write TreeNode::new(value: i32) -> Rc<TreeNode>. Write TreeNode::add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>), which also sets the child's parent. Write sum(&self) -> i32, the total of this node and all its descendants, and depth(&self) -> usize, the number of ancestors, which is 0 for a root.

assistant

use std::cell::RefCell;
use std::rc::{Rc, Weak};

pub struct TreeNode {
    pub value: i32,
    pub parent: RefCell<Weak<TreeNode>>,
    pub children: RefCell<Vec<Rc<TreeNode>>>,
}

impl TreeNode {
    pub fn new(value: i32) -> Rc<TreeNode> {
        Rc::new(TreeNode {
            value,
            parent: RefCell::new(Weak::new()),
            children: RefCell::new(Vec::new()),
        })
    }

    pub fn add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>) {
        child.parent.replace(Rc::downgrade(parent));
        parent.children.borrow_mut().push(child);
    }

    pub fn sum(&self) -> i32 {
        self.value
            + self
                .children
                .borrow()
                .iter()
                .map(|child| child.sum())
                .sum::<i32>()
    }

    pub fn depth(&self) -> usize {
        self.parent
            .borrow()
            .upgrade()
            .map_or(0, |ancestor| 1 + ancestor.depth())
    }
}

Turn #29Raw score: 1

189 in2,369 out2,104 reasoning64 cached2,558 total15.2s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define TreeNode with exactly these fields: value: i32, parent: RefCell<Weak<TreeNode>>, and children: RefCell<Vec<Rc<TreeNode>>>, importing those types from the standard library. Write TreeNode::new(value: i32) -> Rc<TreeNode>. Write TreeNode::add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>), which also sets the child's parent. Write sum(&self) -> i32, the total of this node and all its descendants, and depth(&self) -> usize, the number of ancestors, which is 0 for a root.

assistant

use std::cell::RefCell;
use std::rc::{Rc, Weak};

pub struct TreeNode {
    value: i32,
    parent: RefCell<Weak<TreeNode>>,
    children: RefCell<Vec<Rc<TreeNode>>>,
}

impl TreeNode {
    pub fn new(value: i32) -> Rc<TreeNode> {
        Rc::new(TreeNode {
            value,
            parent: RefCell::new(Weak::new()),
            children: RefCell::new(Vec::new()),
        })
    }

    pub fn add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>) {
        *child.parent.borrow_mut() = Rc::downgrade(parent);
        parent.children.borrow_mut().push(child);
    }

    pub fn sum(&self) -> i32 {
        self.value
            + self
                .children
                .borrow()
                .iter()
                .map(|child| child.sum())
                .sum::<i32>()
    }

    pub fn depth(&self) -> usize {
        let mut depth = 0;
        let mut ancestor = self.parent.borrow().clone();
        while let Some(node) = ancestor.upgrade() {
            depth += 1;
            ancestor = node.parent.borrow().clone();
        }
        depth
    }
}

Turn #30Raw score: 1

189 in2,052 out1,822 reasoning64 cached2,241 total12.5s

user

Write Rust for the 2024 edition on stable, using only the standard library. Answer with one ```rust code block that defines what the question describes. Do not include fn main, tests, examples, explanations, or print statements.

Define TreeNode with exactly these fields: value: i32, parent: RefCell<Weak<TreeNode>>, and children: RefCell<Vec<Rc<TreeNode>>>, importing those types from the standard library. Write TreeNode::new(value: i32) -> Rc<TreeNode>. Write TreeNode::add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>), which also sets the child's parent. Write sum(&self) -> i32, the total of this node and all its descendants, and depth(&self) -> usize, the number of ancestors, which is 0 for a root.

assistant

use std::cell::RefCell;
use std::rc::{Rc, Weak};

pub struct TreeNode {
    pub value: i32,
    pub parent: RefCell<Weak<TreeNode>>,
    pub children: RefCell<Vec<Rc<TreeNode>>>,
}

impl TreeNode {
    pub fn new(value: i32) -> Rc<TreeNode> {
        Rc::new(TreeNode {
            value,
            parent: RefCell::new(Weak::new()),
            children: RefCell::new(Vec::new()),
        })
    }

    pub fn add_child(parent: &Rc<TreeNode>, child: Rc<TreeNode>) {
        *child.parent.borrow_mut() = Rc::downgrade(parent);
        parent.children.borrow_mut().push(child);
    }

    pub fn sum(&self) -> i32 {
        self.value + self.children.borrow().iter().map(|c| c.sum()).sum::<i32>()
    }

    pub fn depth(&self) -> usize {
        match self.parent.borrow().upgrade() {
            Some(ancestor) => 1 + ancestor.depth(),
            None => 0,
        }
    }
}

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