Add problem 1957: Delete Characters to Make Fancy String

src/lib.rs

@@ -1478,6 +1478,7 @@ pub mod problem_1935_maximum_number_of_words_you_can_type;
 pub mod problem_1941_check_if_all_characters_have_equal_number_of_occurrences;
 pub mod problem_1945_sum_of_digits_of_string_after_convert;
 pub mod problem_1952_three_divisors;
+pub mod problem_1957_delete_characters_to_make_fancy_string;
 
 #[cfg(test)]
 mod test_utilities;

src/problem_1957_delete_characters_to_make_fancy_string/iterative.rs

@@ -0,0 +1,52 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn make_fancy_string(s: String) -> String {
+        let mut s = s.into_bytes();
+        let slice = s.as_mut_slice();
+        let mut writer = 0;
+        let mut i = 0;
+        let mut prev = 0;
+        let mut count = 0_u8;
+
+        while let Some(&c) = slice.get(i) {
+            i += 1;
+
+            if c == prev {
+                if count < 2 {
+                    count += 1;
+                } else {
+                    continue;
+                }
+            } else {
+                prev = c;
+                count = 1;
+            }
+
+            slice[writer] = c;
+            writer += 1;
+        }
+
+        s.truncate(writer);
+
+        String::from_utf8(s).unwrap()
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn make_fancy_string(s: String) -> String {
+        Self::make_fancy_string(s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_1957_delete_characters_to_make_fancy_string/mod.rs

@@ -0,0 +1,18 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn make_fancy_string(s: String) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [("leeetcode", "leetcode"), ("aaabaaaa", "aabaa"), ("aab", "aab")];
+
+        for (s, expected) in test_cases {
+            assert_eq!(S::make_fancy_string(s.to_string()), expected);
+        }
+    }
+}