101 lines
2.3 KiB
Rust
101 lines
2.3 KiB
Rust
/**
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* [909] Snakes and Ladders
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*/
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pub struct Solution {}
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// submission codes start here
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use std::collections::VecDeque;
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impl Solution {
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pub fn snakes_and_ladders(board: Vec<Vec<i32>>) -> i32 {
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let n = board.len() * board.len();
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let mut map = Vec::with_capacity(n);
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map.push(0);
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let mut reverse = false;
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let mut index = 1;
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for array in board.iter().rev() {
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let array: Box<dyn Iterator<Item = &i32>> = if reverse {
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Box::new(array.iter().rev())
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} else {
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Box::new(array.iter())
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};
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for &i in array {
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if i == -1 {
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map.push(index);
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} else {
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map.push(i as usize);
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}
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index += 1;
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}
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reverse = !reverse;
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}
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let mut visited = vec![false; n + 1];
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let mut queue = VecDeque::new();
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queue.push_back(1);
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let mut count = 0;
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while !queue.is_empty() {
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let length = queue.len();
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for _ in 0..length {
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let node = queue.pop_front().unwrap();
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if node == n {
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return count;
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}
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for next in (node + 1)..=(node + 6) {
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if next > n {
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continue;
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}
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if !visited[next] {
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visited[next] = true;
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queue.push_back(map[next]);
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}
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}
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}
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count += 1;
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}
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-1
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}
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}
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// submission codes end
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_909_1() {
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assert_eq!(
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Solution::snakes_and_ladders(vec![
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vec![-1, -1, -1, -1, -1, -1],
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vec![-1, -1, -1, -1, -1, -1],
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vec![-1, -1, -1, -1, -1, -1],
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vec![-1, 35, -1, -1, 13, -1],
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vec![-1, -1, -1, -1, -1, -1],
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vec![-1, 15, -1, -1, -1, -1]
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]),
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4
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);
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}
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#[test]
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fn test_909_2() {
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assert_eq!(
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Solution::snakes_and_ladders(vec![vec![-1, -1, -1], vec![-1, 9, 8], vec![-1, 8, 9]]),
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1
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);
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}
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}
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