Add problem 2075: Decode the Slanted Ciphertext

src/lib.rs

@@ -1508,6 +1508,7 @@ pub mod problem_2069_walking_robot_simulation_ii;
 pub mod problem_2070_most_beautiful_item_for_each_query;
 pub mod problem_2073_time_needed_to_buy_tickets;
 pub mod problem_2074_reverse_nodes_in_even_length_groups;
+pub mod problem_2075_decode_the_slanted_ciphertext;
 pub mod problem_2078_two_furthest_houses_with_different_colors;
 pub mod problem_2085_count_common_words_with_one_occurrence;
 pub mod problem_2089_find_target_indices_after_sorting_array;

src/problem_2075_decode_the_slanted_ciphertext/iterative.rs

@@ -0,0 +1,37 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn decode_ciphertext(encoded_text: String, rows: i32) -> String {
+        let rows = rows as u32 as usize;
+        let columns = encoded_text.len() / rows;
+        let mut result = Vec::with_capacity(encoded_text.len());
+        let mut iter = encoded_text.bytes();
+
+        for _ in 0..columns {
+            result.extend(iter.clone().step_by(columns + 1));
+            iter.next();
+        }
+
+        result.truncate(result.iter().rposition(|&c| c != b' ').map_or(0, |i| i + 1));
+
+        String::from_utf8(result).unwrap()
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn decode_ciphertext(encoded_text: String, rows: i32) -> String {
+        Self::decode_ciphertext(encoded_text, rows)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2075_decode_the_slanted_ciphertext/mod.rs

@@ -0,0 +1,23 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn decode_ciphertext(encoded_text: String, rows: i32) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (("ch   ie   pr", 3), "cipher"),
+            (("iveo    eed   l te   olc", 4), "i love leetcode"),
+            (("coding", 1), "coding"),
+            (("", 5), ""),
+        ];
+
+        for ((encoded_text, rows), expected) in test_cases {
+            assert_eq!(S::decode_ciphertext(encoded_text.to_string(), rows), expected);
+        }
+    }
+}