Add problem 1417: Reformat The String

src/lib.rs

@@ -549,6 +549,7 @@ pub mod problem_1387_sort_integers_by_the_power_value;
 pub mod problem_1390_four_divisors;
 pub mod problem_1396_design_underground_system;
 pub mod problem_1405_longest_happy_string;
+pub mod problem_1417_reformat_the_string;
 pub mod problem_1418_display_table_of_food_orders_in_a_restaurant;
 pub mod problem_1433_check_if_a_string_can_break_another_string;
 pub mod problem_1441_build_an_array_with_stack_operations;

src/problem_1417_reformat_the_string/iterative.rs

@@ -0,0 +1,48 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn reformat(s: String) -> String {
+        let mut letter = vec![];
+        let mut digit = vec![];
+        for ch in s.chars() {
+            if ch.is_numeric() {
+                digit.push(ch);
+            } else {
+                letter.push(ch);
+            }
+        }
+        if letter.len().abs_diff(digit.len()) > 1 {
+            return String::new();
+        }
+        let mut result = String::with_capacity(s.len());
+
+        let (a, mut b) = if letter.len() > digit.len() {
+            (letter.into_iter(), digit.into_iter())
+        } else {
+            (digit.into_iter(), letter.into_iter())
+        };
+
+        for ch in a {
+            result.push(ch);
+            if let Some(ch) = b.next() {
+                result.push(ch);
+            }
+        }
+
+        result
+    }
+}
+
+impl super::Solution for Solution {
+    fn reformat(s: String) -> String {
+        Self::reformat(s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_1417_reformat_the_string/mod.rs

@@ -0,0 +1,42 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn reformat(s: String) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+    use crate::test_utilities;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            ("a0b1c2", true),
+            ("leetcode", false),
+            ("1229857369", false),
+            ("covid2019", true),
+        ];
+
+        for (s, expected) in test_cases {
+            let result = S::reformat(s.to_string());
+
+            if expected {
+                assert_eq!(
+                    test_utilities::unstable_sorted(result.bytes()),
+                    test_utilities::unstable_sorted(s.bytes()),
+                );
+
+                let mut iter = result.bytes().map(|c| c.is_ascii_digit());
+                let mut prev = iter.next().unwrap();
+
+                for value in iter {
+                    assert_ne!(value, prev);
+
+                    prev = value;
+                }
+            } else {
+                assert!(result.is_empty());
+            }
+        }
+    }
+}