20240129 Finished

src/problem/mod.rs

@@ -30,4 +30,5 @@ mod p2865_beautiful_towers_i;
 mod p2859_sum_of_values_at_indices_with_k_set_bits;
 mod p2846_minimum_edge_weight_equilibrium_queries_in_a_tree;
 mod p2861_maximum_number_of_alloys;
-mod p365_water_and_jug_problem;
+mod p365_water_and_jug_problem;
+mod p514_freedom_trail;

src/problem/p514_freedom_trail.rs

@@ -0,0 +1,66 @@
+/**
+ * [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);
+    }
+}