Monistus

use std::{collections::VecDeque, io};

const MAX_SIZE: usize = 500_000;

fn main() {
    let mut input = String::with_capacity(MAX_SIZE);
    io::stdin().read_line(&mut input).unwrap();
    let mut buffer = VecDeque::from(Vec::from(input));
    dbg!(buffer.capacity());

    let mut result = String::with_capacity(MAX_SIZE);
    while let Some(byte) = buffer.pop_front() {
        if let Some(n) = (byte as char).to_digit(10) {
            let slice: Vec<u8> = buffer.iter().cloned().take(n as usize).collect();
            slice.iter().rev().for_each(|x| buffer.push_front(*x));
        } else {
            result.push(byte as char);
        }
    }

    println!("{}", result);
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 2

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 3

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 4

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 5

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 6

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 7

Group: 1, 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 8

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 9

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 10

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 11

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 1048575

Test 12

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 13

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287

Test 14

Group: 2

Verdict: ACCEPTED

[input/code.rs:9] buffer.capacity() = 524287