qwen/qwen3.5-9b on Rust Quick Ten

Turn #1Raw score: 1

100 in8,786 out7,815 reasoning8,886 total665.4s

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.

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<char> = s
        .chars()
        .filter(|c| c.is_ascii_alphanumeric())
        .map(|c| c.to_ascii_lowercase())
        .collect();

    chars.iter().eq(chars.iter().rev())
}

Turn #2Raw score: 1

100 in875 out770 reasoning975 total67.8s

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 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 filtered: Vec<char> = s
        .chars()
        .filter(|c| c.is_ascii_alphanumeric())
        .map(|c| c.to_ascii_lowercase())
        .collect();
    
    let len = filtered.len();
    for i in 0..len / 2 {
        if filtered[i] != filtered[len - 1 - i] {
            return false;
        }
    }
    true
}

Turn #3Raw score: 0

100 in659 out602 reasoning759 total51.7s

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 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

fn is_palindrome(s: &str) -> bool {
    let filtered: Vec<char> = s
        .chars()
        .filter(|c| c.is_ascii_alphanumeric())
        .map(|c| c.to_ascii_lowercase())
        .collect();
    
    filtered == filtered.iter().rev().collect::<Vec<char>>()
}

Turn #4Raw score: 1

110 in3,476 out3,190 reasoning3,586 total319.0s

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 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;

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

Turn #5Raw score: 1

110 in3,528 out3,322 reasoning3,638 total273.1s

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;

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

Turn #6Raw score: 1

110 in5,998 out5,276 reasoning6,108 total471.5s

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;

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

Turn #7Raw score: 1

107 in6,396 out5,601 reasoning6,503 total650.0s

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 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

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

Turn #8Raw score: 1

107 in6,118 out5,563 reasoning6,225 total492.2s

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 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

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

Turn #9Raw score: 1

107 in2,677 out2,358 reasoning2,784 total278.2s

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 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

pub fn longest<'a>(s1: &'a str, s2: &'a str) -> &'a str {
    if s1.len() >= s2.len() {
        s1
    } else {
        s2
    }
}

Turn #10Raw score: 1

176 in8,940 out6,774 reasoning9,116 total567.9s

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 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;

pub fn parse_pair<T: FromStr>(s: &str, sep: char) -> Option<(T, T)> {
    s.split_once(sep)
        .and_then(|(left, right)| {
            T::from_str(left)
                .ok()
                .and_then(|l| T::from_str(right).ok().map(|r| (l, r)))
        })
}

Turn #11Raw score: 0

176 in6,033 out4,686 reasoning6,209 total401.7s

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 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 mut parts = s.splitn(2, sep);
    let left = parts.next()?;
    let right = parts.next()?;
    let left_val = T::from_str(left)?;
    let right_val = T::from_str(right)?;
    Some((left_val, right_val))
}

Turn #12Raw score: 0

176 in32,000 out20,896 reasoning32,176 total1697.8s

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)).

Turn #13Raw score: 1

128 in626 out546 reasoning754 total56.7s

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

pub fn compose<F, G, A, B, C>(f: F, g: G) -> Box<dyn Fn(A) -> C>
where
    F: Fn(A) -> B + 'static,
    G: Fn(B) -> C + 'static,
{
    Box::new(move |x: A| g(f(x)))
}

Turn #14Raw score: 0

128 in669 out515 reasoning797 total61.0s

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 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

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

Turn #15Raw score: 0

128 in558 out551 reasoning686 total51.9s

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

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

Turn #16Raw score: 0

145 in11,157 out8,653 reasoning11,302 total665.0s

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 {
    a: u64,
    b: u64,
    exhausted: bool,
}

impl Fib {
    pub fn new() -> Self {
        Fib {
            a: 0,
            b: 1,
            exhausted: false,
        }
    }
}

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<Self::Item> {
        if self.exhausted {
            return None;
        }

        let current = self.a;
        self.a = self.b;
        
        // Check if next Fibonacci number (self.a + self.b) would overflow
        if let Some(next_b) = self.a.checked_add(self.b) {
            self.b = next_b;
            Some(current)
        } else {
            // Overflow detected, stop yielding
            self.exhausted = true;
            None
        }
    }
}

Turn #17Raw score: 0

145 in22,215 out16,456 reasoning22,360 total1525.7s

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 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 {
    a: u64,
    b: u64,
}

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

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<Self::Item> {
        let current = self.a;
        let next_a = self.a.checked_add(self.b);

        if let Some(val) = next_a {
            self.a = self.b;
            self.b = val;
        } else {
            // Overflow detected, stop iterator
            // This handles the case where the next Fibonacci number doesn't fit
            return None;
        }

        Some(current)
    }
}

Turn #18Raw score: 0

145 in879 out650 reasoning1,024 total50.9s

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.

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 {
    a: u64,
    b: u64,
    done: bool,
}

impl Fib {
    pub fn new() -> Self {
        Fib { a: 0, b: 1, done: false }
    }
}

impl Iterator for Fib {
    type Item = u64;

    fn next(&mut self) -> Option<Self::Item> {
        if self.done {
            return None;
        }

        let a = self.a;

        // Check if a + b would overflow
        let (sum, overflow) = a.overflowing_add(self.b);
        if overflow {
            self.done = true;
            return None;
        }

        // Check if next iteration (b + sum) would overflow
        let (next_sum, next_overflow) = self.b.overflowing_add(sum);
        if next_overflow {
            self.done = true;
            return None;
        }

        self.a = self.b;
        self.b = sum;

        Some(a)
    }
}

Turn #19Raw score: 1

249 in9,543 out7,808 reasoning9,792 total545.9s

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.

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;

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

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

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

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

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    if s.is_empty() {
        return Err(TempError::Empty);
    }

    let unit = s.chars().last().expect("Non-empty string");
    if unit == 'C' || unit == 'F' {
        let number_str = &s[..s.len() - 1];
        match number_str.parse::<f64>() {
            Ok(val) => {
                let celsius = if unit == 'F' {
                    (val - 32.0) * 5.0 / 9.0
                } else {
                    val
                };
                Ok(celsius)
            }
            Err(e) => Err(TempError::BadNumber(e)),
        }
    } else {
        Err(TempError::BadUnit(unit))
    }
}

Turn #20Raw score: 1

249 in14,372 out11,606 reasoning14,621 total670.5s

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 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"),
            TempError::BadUnit(c) => write!(f, "BadUnit({:?})", c),
            TempError::BadNumber(e) => write!(f, "BadNumber({})", e),
        }
    }
}

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

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

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    if s.is_empty() {
        return Err(TempError::Empty);
    }

    let unit = s.chars().last().ok_or(TempError::Empty)?;

    if unit != 'C' && unit != 'F' {
        return Err(TempError::BadUnit(unit));
    }

    let num_str = &s[..s.len() - 1];

    match num_str.parse::<f64>() {
        Ok(val) => Ok(if unit == 'F' {
            (val - 32.0) * 5.0 / 9.0
        } else {
            val
        }),
        Err(e) => Err(TempError::BadNumber(e)),
    }
}

Turn #21Raw score: 1

249 in15,014 out12,509 reasoning15,263 total690.0s

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;
use std::num::ParseFloatError;

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

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

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

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

pub fn parse_temp(s: &str) -> Result<f64, TempError> {
    if s.is_empty() {
        return Err(TempError::Empty);
    }

    let unit = s.chars().last().ok_or(TempError::Empty)?;
    if unit != 'C' && unit != 'F' {
        return Err(TempError::BadUnit(unit));
    }

    let num_str = &s[..s.len() - unit.len_utf8()];
    let value = num_str.parse::<f64>()?;

    if unit == 'F' {
        Ok((value - 32.0) * 5.0 / 9.0)
    } else {
        Ok(value)
    }
}

Turn #22Raw score: 0

147 in12,012 out10,010 reasoning12,159 total451.2s

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 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

pub fn parallel_sum(data: &[u64], workers: usize) -> u64 {
    if workers == 0 {
        panic!("workers must be > 0");
    }
    if data.is_empty() {
        return 0;
    }

    let len = data.len();
    let chunk_size = len.saturating_add(workers - 1) / workers;

    let mut handles = Vec::with_capacity(workers);

    for i in 0..workers {
        let start = i.saturating_mul(chunk_size);
        let end = start.saturating_add(chunk_size);
        let end = end.min(len);

        if start >= end {
            continue;
        }

        let slice = &data[start..end];
        let handle = std::thread::spawn(move || {
            slice.iter().sum()
        });
        handles.push(handle);
    }

    let mut total = 0u64;
    for handle in handles {
        total += handle.join().expect("thread panicked");
    }
    total
}

Turn #23Raw score: 0

147 in27,719 out28,420 reasoning27,866 total1166.3s

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 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.

Turn #24Raw score: 0

147 in32,000 out22,631 reasoning32,147 total1328.7s

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 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.

Turn #25Raw score: 0

135 in25,587 out19,784 reasoning25,722 total1089.9s

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.

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::Peekable;

pub trait PairsExt {
    fn pairs(&self) -> PairsIterator<Self>;
}

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

impl<I> PairsExt for I
where
    I: Iterator,
    I::Item: Clone,
{
    fn pairs(&self) -> PairsIterator<Self> {
        PairsIterator {
            iter: Peekable::new(self),
            prev: None,
        }
    }
}

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

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

Turn #26Raw score: 0

135 in32,000 out26,407 reasoning32,135 total1352.5s

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 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.

Turn #27Raw score: 0

135 in22,074 out18,260 reasoning22,209 total707.9s

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.

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.

Turn #28Raw score: 0

193 in12,204 out9,591 reasoning12,397 total448.8s

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

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>) {
        parent.children.borrow_mut().push(child.clone());
        let _ = mem::replace(&mut child.borrow_mut().parent.borrow_mut(), Weak::downgrade(parent));
    }

    pub fn sum(&self) -> i32 {
        let mut total = self.value;
        for child_rc in self.children.borrow() {
            total += child_rc.borrow().sum();
        }
        total
    }

    pub fn depth(&self) -> usize {
        if self.parent.borrow().upgrade().is_none() {
            0
        } else {
            self.parent.borrow().upgrade().unwrap().depth() + 1
        }
    }
}

Turn #29Raw score: 0

193 in9,611 out7,503 reasoning9,804 total371.9s

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.

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};

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>) {
        parent.children.borrow_mut().push(child.clone());
        *child.parent.borrow_mut() = Rc::downgrade(parent);
    }

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

    pub fn depth(&self) -> usize {
        self.parent.borrow().upgrade().map(|p| p.depth() + 1).unwrap_or(0)
    }
}

Turn #30Raw score: 0

193 in32,000 out29,030 reasoning32,193 total1056.4s

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 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.

Run Detail

Recorded for these videos

Turns (30)