#996759 (Rust) No.887 Collatz

• 問題: No.887 Collatz
• ユーザー: tomerun
• 提出日時: 2024-07-21 03:54:29
• 言語: Rust (1.77.0 + proconio)
• 結果: AC
• 実行時間: 1 ms / 2,000 ms
• コード長: 2,980 bytes
• コンパイル時間: 11,097 ms
• コンパイル使用メモリ: 378,756 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-21 03:54:44
• 合計ジャッジ時間: 12,881 ms
• ジャッジサーバーID （参考情報）: judge3 / judge2

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	0 ms; 5,248 KB
testcase_01	AC	1 ms; 5,376 KB
testcase_02	AC	1 ms; 5,376 KB
testcase_03	AC	0 ms; 5,376 KB
testcase_04	AC	1 ms; 5,376 KB
testcase_05	AC	0 ms; 5,376 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	1 ms; 5,376 KB
testcase_08	AC	1 ms; 5,376 KB
testcase_09	AC	1 ms; 5,376 KB
testcase_10	AC	1 ms; 5,376 KB
testcase_11	AC	1 ms; 5,376 KB
testcase_12	AC	1 ms; 5,376 KB
testcase_13	AC	1 ms; 5,376 KB
testcase_14	AC	1 ms; 5,376 KB
testcase_15	AC	1 ms; 5,376 KB
testcase_16	AC	1 ms; 5,376 KB
testcase_17	AC	1 ms; 5,376 KB
testcase_18	AC	1 ms; 5,376 KB
testcase_19	AC	1 ms; 5,376 KB
testcase_20	AC	1 ms; 5,376 KB
testcase_21	AC	1 ms; 5,376 KB
testcase_22	AC	1 ms; 5,376 KB
testcase_23	AC	1 ms; 5,376 KB
testcase_24	AC	1 ms; 5,376 KB
testcase_25	AC	1 ms; 5,376 KB
testcase_26	AC	1 ms; 5,376 KB
testcase_27	AC	0 ms; 5,376 KB
testcase_28	AC	1 ms; 5,376 KB
testcase_29	AC	0 ms; 5,376 KB
testcase_30	AC	1 ms; 5,376 KB

ソースコード

#![allow(unused_imports)]
#![allow(dead_code)]
use std::collections::{HashMap, HashSet};
use std::io::{self, BufRead, BufReader, Read, Stdin};
use std::iter;
use std::mem;
use std::str::FromStr;
use std::string::String;

#[derive(Debug)]
pub struct Scanner<R> {
    reader: BufReader<R>,
}

fn scanner() -> Scanner<Stdin> {
    Scanner::new(io::stdin())
}

impl<R: io::Read> Scanner<R> {
    pub fn new(read: R) -> Scanner<R> {
        Scanner {
            reader: BufReader::new(read),
        }
    }

    pub fn next_str(&mut self) -> Option<String> {
        let mut buf = [0; 1];
        let size = self.reader.read(&mut buf).unwrap();
        if size == 0 {
            None
        } else {
            self.skip_whitespace(&mut buf)?;
            let mut v = vec![buf[0]];
            loop {
                let size = self.reader.read(&mut buf).unwrap();
                if size == 0 || buf[0].is_ascii_whitespace() {
                    break;
                }
                v.push(buf[0]);
            }
            Some(String::from_utf8(v).unwrap())
        }
    }

    pub fn next_line(&mut self) -> String {
        let mut line = String::new();
        self.reader.read_line(&mut line).unwrap();
        line
    }

    pub fn vec<S: FromStr>(&mut self, size: i32) -> Vec<S> {
        let mut v: Vec<S> = vec![];
        for _ in 0..size {
            let token = self.next_str().unwrap();
            v.push(S::from_str(&token).ok().unwrap());
        }
        v
    }

    pub fn next_as<S: FromStr>(&mut self) -> Option<S> {
        let s = self.next_str()?;
        S::from_str(&s).ok()
    }

    pub fn str(&mut self) -> String {
        self.next_str().unwrap()
    }

    pub fn i32(&mut self) -> i32 {
        self.next_as::<i32>().unwrap()
    }

    pub fn u32(&mut self) -> u32 {
        self.next_as::<u32>().unwrap()
    }

    pub fn i64(&mut self) -> i64 {
        self.next_as::<i64>().unwrap()
    }

    pub fn u64(&mut self) -> u64 {
        self.next_as::<u64>().unwrap()
    }

    pub fn usize(&mut self) -> usize {
        self.next_as::<usize>().unwrap()
    }

    pub fn f32(&mut self) -> f32 {
        self.next_as::<f32>().unwrap()
    }

    pub fn f64(&mut self) -> f64 {
        self.next_as::<f64>().unwrap()
    }

    fn skip_whitespace(&mut self, mut buf: &mut [u8]) -> Option<u8> {
        loop {
            if !buf[0].is_ascii_whitespace() {
                return Some(buf[0]);
            }
            let size = self.reader.read(&mut buf).unwrap();
            if size == 0 {
                return None;
            }
        }
    }
}

fn yesno(b: bool) -> &'static str {
    if b {
        "Yes"
    } else {
        "No"
    }
}

// end of library

fn main() {
    let mut sc = scanner();
    let mut n = sc.i32();
    let mut i = 0;
    let mut max = n;
    while n != 1 {
        n = if n % 2 == 0 { n / 2 } else { n * 3 + 1 };
        max = max.max(n);
        i += 1
    }
    println!("{}\n{}", i, max);
}