Add problem 0709: To Lower Case

src/lib.rs

@@ -345,6 +345,7 @@ pub mod problem_0665_non_decreasing_array;
 pub mod problem_0673_number_of_longest_increasing_subsequence;
 pub mod problem_0674_longest_continuous_increasing_subsequence;
 pub mod problem_0677_map_sum_pairs;
+pub mod problem_0709_to_lower_case;
 pub mod problem_0717_1_bit_and_2_bit_characters;
 pub mod problem_0720_longest_word_in_dictionary;
 pub mod problem_0738_monotone_increasing_digits;

src/problem_0709_to_lower_case/cheating.rs

@@ -0,0 +1,21 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn to_lower_case(s: String) -> String {
+        s.to_lowercase()
+    }
+}
+
+impl super::Solution for Solution {
+    fn to_lower_case(str: String) -> String {
+        Self::to_lower_case(str)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_0709_to_lower_case/iterative.rs

@@ -0,0 +1,27 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn to_lower_case(s: String) -> String {
+        let mut s = s.into_bytes();
+        for ch in &mut s {
+            if *ch >= b'A' && *ch <= b'Z' {
+                *ch = *ch - b'A' + b'a';
+            }
+        }
+        String::from_utf8(s).unwrap()
+    }
+}
+
+impl super::Solution for Solution {
+    fn to_lower_case(str: String) -> String {
+        Self::to_lower_case(str)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_0709_to_lower_case/mod.rs

@@ -0,0 +1,19 @@
+pub mod cheating;
+pub mod iterative;
+
+pub trait Solution {
+    fn to_lower_case(str: String) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [("Hello", "hello"), ("here", "here"), ("LOVELY", "lovely")];
+
+        for (str, expected) in test_cases {
+            assert_eq!(S::to_lower_case(str.to_string()), expected);
+        }
+    }
+}