Add problem 2000: Reverse Prefix of Word

Author: Spxg

src/lib.rs

@@ -638,6 +638,7 @@ pub mod problem_1929_concatenation_of_array;
 pub mod problem_1935_maximum_number_of_words_you_can_type;
 pub mod problem_1961_check_if_string_is_a_prefix_of_array;
 pub mod problem_1962_remove_stones_to_minimize_the_total;
+pub mod problem_2000_reverse_prefix_of_word;
 pub mod problem_2032_two_out_of_three;
 pub mod problem_2108_find_first_palindromic_string_in_the_array;
 pub mod problem_2138_divide_a_string_into_groups_of_size_k;

src/problem_2000_reverse_prefix_of_word/iterative.rs

@@ -0,0 +1,25 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn reverse_prefix(word: String, ch: char) -> String {
+        let mut bytes = word.into_bytes();
+        if let Some(pos) = bytes.iter().position(|&x| x == ch as u8) {
+            bytes[0..=pos].reverse();
+        }
+        String::from_utf8(bytes).unwrap()
+    }
+}
+
+impl super::Solution for Solution {
+    fn reverse_prefix(word: String, ch: char) -> String {
+        Self::reverse_prefix(word, ch)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2000_reverse_prefix_of_word/mod.rs

@@ -0,0 +1,22 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn reverse_prefix(word: String, ch: char) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (("abcdefd", 'd'), "dcbaefd"),
+            (("xyxzxe", 'z'), "zxyxxe"),
+            (("abcd", 'z'), "abcd"),
+        ];
+
+        for ((word, ch), expected) in test_cases {
+            assert_eq!(S::reverse_prefix(word.to_string(), ch), expected);
+        }
+    }
+}