Add problem 2325: Decode the Message

src/lib.rs

@@ -1724,6 +1724,7 @@ pub mod problem_2317_maximum_xor_after_operations;
 pub mod problem_2319_check_if_matrix_is_x_matrix;
 pub mod problem_2320_count_number_of_ways_to_place_houses;
 pub mod problem_2321_maximum_score_of_spliced_array;
+pub mod problem_2325_decode_the_message;
 
 #[cfg(test)]
 mod test_utilities;

src/problem_2325_decode_the_message/iterative.rs

@@ -0,0 +1,47 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn decode_message(key: String, message: String) -> String {
+        let mut mapping = [0_u8; 26];
+        let mut next = b'a';
+
+        for from in key.into_bytes() {
+            if let Some(slot @ 0) = mapping.get_mut(usize::from(from).wrapping_sub(usize::from(b'a'))) {
+                *slot = next;
+                next += 1;
+
+                if next > b'z' {
+                    break;
+                }
+            }
+        }
+
+        let mut result = message.into_bytes();
+
+        for from in &mut result {
+            if let Some(&to) = mapping.get(usize::from(*from).wrapping_sub(usize::from(b'a'))) {
+                *from = to;
+            }
+        }
+
+        String::from_utf8(result).unwrap()
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn decode_message(key: String, message: String) -> String {
+        Self::decode_message(key, message)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2325_decode_the_message/mod.rs

@@ -0,0 +1,27 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn decode_message(key: String, message: String) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (
+                ("the quick brown fox jumps over the lazy dog", "vkbs bs t suepuv"),
+                "this is a secret",
+            ),
+            (
+                ("eljuxhpwnyrdgtqkviszcfmabo", "zwx hnfx lqantp mnoeius ycgk vcnjrdb"),
+                "the five boxing wizards jump quickly",
+            ),
+        ];
+
+        for ((key, message), expected) in test_cases {
+            assert_eq!(S::decode_message(key.to_string(), message.to_string()), expected);
+        }
+    }
+}