diff --git a/src/lib.rs b/src/lib.rs
index d866391b..8e4bb129 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1424,6 +1424,7 @@ pub mod problem_2063_vowels_of_all_substrings;
 pub mod problem_2068_check_whether_two_strings_are_almost_equivalent;
 pub mod problem_2069_walking_robot_simulation_ii;
 pub mod problem_2070_most_beautiful_item_for_each_query;
+pub mod problem_2085_count_common_words_with_one_occurrence;
 
 #[cfg(test)]
 mod test_utilities;
diff --git a/src/problem_2085_count_common_words_with_one_occurrence/hash_map.rs b/src/problem_2085_count_common_words_with_one_occurrence/hash_map.rs
new file mode 100644
index 00000000..4dd03071
--- /dev/null
+++ b/src/problem_2085_count_common_words_with_one_occurrence/hash_map.rs
@@ -0,0 +1,53 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn count_words(words1: Vec<String>, words2: Vec<String>) -> i32 {
+        let mut states = HashMap::<_, u8>::new();
+
+        for word in words1 {
+            states.entry(word).and_modify(|c| *c = 1).or_insert(0);
+        }
+
+        let mut result = 0;
+
+        for word in words2 {
+            if let Entry::Occupied(mut entry) = states.entry(word) {
+                let state = entry.get_mut();
+
+                if *state == 0 {
+                    result += 1;
+                    *state = 2;
+                } else {
+                    if *state == 2 {
+                        result -= 1;
+                    }
+
+                    entry.remove();
+                }
+            }
+        }
+
+        result
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn count_words(words1: Vec<String>, words2: Vec<String>) -> i32 {
+        Self::count_words(words1, words2)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}
diff --git a/src/problem_2085_count_common_words_with_one_occurrence/mod.rs b/src/problem_2085_count_common_words_with_one_occurrence/mod.rs
new file mode 100644
index 00000000..1a2c20b9
--- /dev/null
+++ b/src/problem_2085_count_common_words_with_one_occurrence/mod.rs
@@ -0,0 +1,34 @@
+pub mod hash_map;
+
+pub trait Solution {
+    fn count_words(words1: Vec<String>, words2: Vec<String>) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (
+                (
+                    &["leetcode", "is", "amazing", "as", "is"] as &[_],
+                    &["amazing", "leetcode", "is"] as &[_],
+                ),
+                2,
+            ),
+            ((&["b", "bb", "bbb"], &["a", "aa", "aaa"]), 0),
+            ((&["a", "ab"], &["a", "a", "a", "ab"]), 1),
+        ];
+
+        for ((words1, words2), expected) in test_cases {
+            assert_eq!(
+                S::count_words(
+                    words1.iter().copied().map(str::to_string).collect(),
+                    words2.iter().copied().map(str::to_string).collect()
+                ),
+                expected,
+            );
+        }
+    }
+}