leetcode/src/problem/p514_freedom_trail.rs
2024-01-29 14:54:25 +08:00

67 lines
1.8 KiB
Rust

/**
* [514] Freedom Trail
*/
pub struct Solution {}
// submission codes start here
use std::collections::HashMap;
impl Solution {
pub fn find_rotate_steps(ring: String, key: String) -> i32 {
let mut map = HashMap::new();
for (index, value) in ring.chars().enumerate() {
let entry = map.entry(value).or_insert(Vec::new());
entry.push(index);
}
let mut dp = Vec::with_capacity(key.len());
for _ in 0..key.len() {
dp.push(vec![i32::MAX;ring.len()]);
}
let key: Vec<char> = key.chars().collect();
for (index, value) in key.iter().enumerate() {
let pos = map.get(&value).unwrap();
if index == 0 {
for i in pos {
dp[index][*i] = ((*i).min(ring.len() - *i) + 1) as i32;
}
} else {
for i in pos {
let last = key[index - 1];
let last_pos = map.get(&last).unwrap();
for j in last_pos {
let now = *i as i32;
let last = *j as i32;
dp[index][*i] = dp[index][*i].min(
dp[index - 1][*j] + (now - last).abs().min(
ring.len() as i32 - (now - last).abs()) + 1
)
}
}
}
}
*dp[key.len() - 1].iter().min().unwrap()
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_514() {
assert_eq!(Solution::find_rotate_steps("godding".to_string(), "gd".to_string()), 4);
assert_eq!(Solution::find_rotate_steps("godding".to_string(), "godding".to_string()), 13);
}
}