CSES - Datatähti 2025 alku

Submission details
Task:	Robotti
Sender:	villsukka
Submission time:	2024-10-29 14:23:21 +0200
Language:	Rust (2021)
Status:	READY
Result:	100

Feedback
group	verdict	score
#1	ACCEPTED	30
#2	ACCEPTED	70

Test results
test	verdict	time	group
#1	ACCEPTED	0.00 s	1, 2	details
#2	ACCEPTED	0.00 s	1, 2	details
#3	ACCEPTED	0.00 s	1, 2	details
#4	ACCEPTED	0.00 s	1, 2	details
#5	ACCEPTED	0.00 s	1, 2	details
#6	ACCEPTED	0.00 s	1, 2	details
#7	ACCEPTED	0.00 s	1, 2	details
#8	ACCEPTED	0.00 s	1, 2	details
#9	ACCEPTED	0.00 s	1, 2	details
#10	ACCEPTED	0.00 s	1, 2	details
#11	ACCEPTED	0.00 s	1, 2	details
#12	ACCEPTED	0.00 s	2	details
#13	ACCEPTED	0.00 s	2	details
#14	ACCEPTED	0.00 s	2	details
#15	ACCEPTED	0.00 s	2	details
#16	ACCEPTED	0.00 s	2	details
#17	ACCEPTED	0.00 s	2	details
#18	ACCEPTED	0.01 s	2	details
#19	ACCEPTED	0.01 s	2	details
#20	ACCEPTED	0.00 s	2	details
#21	ACCEPTED	0.01 s	2	details
#22	ACCEPTED	0.01 s	2	details
#23	ACCEPTED	0.01 s	2	details
#24	ACCEPTED	0.00 s	2	details

Code

#[cfg(test)]
mod tests;

use std::{io::stdin, ops::Add};
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum RoomType {
    Robot,
    Coin,
    Empty,
}

#[derive(Debug, Clone, Copy)]
enum Ordering {
    Less,
    Greater,
    Equal,
    BothInvalid,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
enum Direction {
    Left,
    Right,
}

struct Pointer {
    pos: usize,
    max_len: usize,
    direction: Direction,
}

impl Pointer {
    ///True Means Incremented
    fn try_increment(&mut self) -> bool {
        let num = match self.direction {
            Direction::Left => self.pos.checked_sub(1),
            Direction::Right => {
                if self.pos + 1 <= self.max_len {
                    Some(self.pos.add(1))
                } else {
                    None
                }
            }
        };

        match num {
            Some(x) => {
                self.pos = x;
                true
            }
            None => false,
        }
    }

    fn cmp_with_start(&self, other: &Self, start_pos: usize) -> Ordering {
        let dist_to_self = self.dist_from_start(start_pos);
        let dist_to_other = other.dist_from_start(start_pos);

        match (self.is_edged(), other.is_edged()) {
            (true, true) => Ordering::BothInvalid,
            (true, false) => Ordering::Greater,
            (false, true) => Ordering::Less,
            (false, false) => match dist_to_self.cmp(&dist_to_other) {
                std::cmp::Ordering::Less => Ordering::Less,
                std::cmp::Ordering::Equal => Ordering::Equal,
                std::cmp::Ordering::Greater => Ordering::Greater,
            },
        }
        //Add comparison which fails or sum when is edged
    }

    fn dist_from_start(&self, start_pos: usize) -> usize {
        match self.direction {
            Direction::Left => start_pos - self.pos,
            Direction::Right => self.pos - start_pos,
        }
    }

    fn is_edged(&self) -> bool {
        match self.direction {
            Direction::Left => self.pos <= 0,
            Direction::Right => self.pos >= self.max_len,
        }
    }
}

impl From<char> for RoomType {
    fn from(value: char) -> Self {
        match value {
            'R' => RoomType::Robot,
            '*' => RoomType::Coin,
            '.' => RoomType::Empty,
            _ => panic!(),
        }
    }
}

fn main() {
    let mut line = String::new();

    stdin().read_line(&mut line).unwrap();
    let len: usize = line.strip_suffix('\n').unwrap_or(&line).parse().unwrap();

    line = "".to_string();

    stdin().read_line(&mut line).unwrap();

    let (steps, coins) = do_challenge(line, len);

    println!("{} {}", steps, coins)
}

fn do_challenge(line: String, len: usize) -> (usize, i32) {
    let mut arr: Vec<RoomType> = line
        .strip_suffix('\n')
        .unwrap()
        .chars()
        .map(|c| c.into())
        .collect();

    let mut robot_pos = arr
        .iter()
        .position(|x| *x == RoomType::Robot)
        .expect("No robot");

    let mut coin_count = 0;
    let mut steps = 0;

    let mut lp = Pointer {
        pos: robot_pos,
        max_len: len - 1,
        direction: Direction::Left,
    };
    let mut rp = Pointer {
        direction: Direction::Right,
        ..lp
    };

    loop {
        match lp.cmp_with_start(&rp, robot_pos) {
            Ordering::Less => {
                lp.try_increment();
            }
            Ordering::Greater => {
                rp.try_increment();
            }
            Ordering::Equal => {
                lp.try_increment();
                rp.try_increment();
            }
            Ordering::BothInvalid => break,
        }

        match (arr[lp.pos] == RoomType::Coin, arr[rp.pos] == RoomType::Coin) {
            (true, true) => break,
            (true, false) => {
                steps += lp.dist_from_start(robot_pos);
                robot_pos = lp.pos;
                coin_count += 1;
                arr[lp.pos] = RoomType::Empty;
            }
            (false, true) => {
                steps += rp.dist_from_start(robot_pos);
                robot_pos = rp.pos;
                coin_count += 1;
                arr[rp.pos] = RoomType::Empty;
            }
            (false, false) => continue,
        }
    }

    (steps, coin_count)
}

Test details

Test 1

Group: 1, 2

Verdict: ACCEPTED

input
`1 R` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
`10 ...R......` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
`10 .R...*` view save

correct output
`12 5` view save

user output
`12 5` view save

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
`10 *R****` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 5

Group: 1, 2

Verdict: ACCEPTED

input
`1000 R................................` view save

correct output
`947 9` view save

user output
`947 9` view save

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
`1000 .................................` view save

correct output
`886 9` view save

user output
`886 9` view save

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
`1000 .........................` view save

correct output
`1287 400` view save

user output
`1287 400` view save

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
`1000 **********.***************...` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 9

Group: 1, 2

Verdict: ACCEPTED

input
`1000 ******************************...` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 10

Group: 1, 2

Verdict: ACCEPTED

input
`1000 R*****************************...` view save

correct output
`999 999` view save

user output
`999 999` view save

Test 11

Group: 1, 2

Verdict: ACCEPTED

input
`1000 ******************************...` view save

correct output
`999 999` view save

user output
`999 999` view save

Test 12

Group: 2

Verdict: ACCEPTED

input
`10000 .......*...................*...` view save

correct output
`10971 999` view save

user output
`10971 999` view save

Test 13

Group: 2

Verdict: ACCEPTED

input
`10000 ...........................` view save

correct output
`9999 999` view save

user output
`9999 999` view save

Test 14

Group: 2

Verdict: ACCEPTED

input
`10000 ...............*.....` view save

correct output
`18766 5000` view save

user output
`18766 5000` view save

Test 15

Group: 2

Verdict: ACCEPTED

input
`10000 R*****************************...` view save

correct output
`9999 9999` view save

user output
`9999 9999` view save

Test 16

Group: 2

Verdict: ACCEPTED

input
`10000 ******************************...` view save

correct output
`9999 9999` view save

user output
`9999 9999` view save

Test 17

Group: 2

Verdict: ACCEPTED

input
`200000 .................................` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 18

Group: 2

Verdict: ACCEPTED

input
`200000 .................................` view save

correct output
`299934 10000` view save

user output
`299934 10000` view save

Test 19

Group: 2

Verdict: ACCEPTED

input
`200000 ............*...*....` view save

correct output
`299998 100000` view save

user output
`299998 100000` view save

Test 20

Group: 2

Verdict: ACCEPTED

input
`200000 ******************************...` view save

correct output
`0 0` view save

user output
`0 0` view save

Test 21

Group: 2

Verdict: ACCEPTED

input
`200000 R................................` view save

correct output
`133765 3` view save

user output
`133765 3` view save

Test 22

Group: 2

Verdict: ACCEPTED

input
`200000 R................................` view save

correct output
`199982 5000` view save

user output
`199982 5000` view save

Test 23

Group: 2

Verdict: ACCEPTED

input
`200000 R*****************************...` view save

correct output
`199999 199999` view save

user output
`199999 199999` view save

Test 24

Group: 2

Verdict: ACCEPTED

input
`200000 ******************************...` view save

correct output
`199999 199999` view save

user output
`199999 199999` view save

Datatähti 2025 alku

Robotti

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Test 17

Test 18

Test 19

Test 20

Test 21

Test 22

Test 23

Test 24

Tasks

Submissions (villsukka)