Add problem 3137: Minimum Number of Operations to Make Word K-Periodic

Author: EFanZh

src/lib.rs

@@ -2101,6 +2101,7 @@ pub mod problem_3127_make_a_square_with_the_same_color;
 pub mod problem_3131_find_the_integer_added_to_array_i;
 pub mod problem_3133_minimum_array_end;
 pub mod problem_3136_valid_word;
+pub mod problem_3137_minimum_number_of_operations_to_make_word_k_periodic;
 pub mod problem_3350_adjacent_increasing_subarrays_detection_ii;
 
 #[cfg(test)]

src/problem_3137_minimum_number_of_operations_to_make_word_k_periodic/hash_map.rs

@@ -0,0 +1,41 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+use std::collections::HashMap;
+use std::collections::hash_map::Entry;
+use std::num::NonZeroUsize;
+
+impl Solution {
+    pub fn minimum_operations_to_make_k_periodic(word: String, k: i32) -> i32 {
+        let k = NonZeroUsize::new(k.cast_unsigned() as _).unwrap();
+        let mut counts = HashMap::<_, u32>::new();
+
+        word.as_bytes()
+            .chunks_exact(k.get())
+            .for_each(|chunk| match counts.entry(chunk) {
+                Entry::Occupied(occupied_entry) => *occupied_entry.into_mut() += 1,
+                Entry::Vacant(vacant_entry) => {
+                    vacant_entry.insert(1);
+                }
+            });
+
+        ((word.len() / k) as u32 - counts.values().copied().fold(0, u32::max)).cast_signed()
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn minimum_operations_to_make_k_periodic(word: String, k: i32) -> i32 {
+        Self::minimum_operations_to_make_k_periodic(word, k)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_3137_minimum_number_of_operations_to_make_word_k_periodic/mod.rs

@@ -0,0 +1,18 @@
+pub mod hash_map;
+
+pub trait Solution {
+    fn minimum_operations_to_make_k_periodic(word: String, k: i32) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [(("leetcodeleet", 4), 1), (("leetcoleet", 2), 3)];
+
+        for ((word, k), expected) in test_cases {
+            assert_eq!(S::minimum_operations_to_make_k_periodic(word.to_string(), k), expected);
+        }
+    }
+}