diff --git a/src/lib.rs b/src/lib.rs
index 2f338b3..144c1b0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
 #[macro_use]
 pub mod util;
 pub mod problem;
+pub mod week_385;
diff --git a/src/week_385/mod.rs b/src/week_385/mod.rs
new file mode 100644
index 0000000..cffe341
--- /dev/null
+++ b/src/week_385/mod.rs
@@ -0,0 +1,3 @@
+mod problem1;
+mod problem2;
+mod problem3;
diff --git a/src/week_385/problem1.rs b/src/week_385/problem1.rs
new file mode 100644
index 0000000..89b8a05
--- /dev/null
+++ b/src/week_385/problem1.rs
@@ -0,0 +1,39 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn count_prefix_suffix_pairs(words: Vec<String>) -> i32 {
+        let mut result = 0;
+        let words: Vec<Vec<char>> = words.iter()
+            .map(|s| {s.chars().collect()})
+            .collect();
+        
+        for j in 1..words.len() {
+            for i in 0..j {
+                if Solution::is_prefix_and_suffix(&words[i], &words[j]) {
+                    result += 1;
+                }
+            }
+        }
+
+        result
+    }
+
+    fn is_prefix_and_suffix(str1: &Vec<char>, str2: &Vec<char>) -> bool {
+        if str1.len() > str2.len() {
+            return false;
+        }
+
+        let mut prefix = 0;
+        let mut suffix = str2.len() - str1.len();
+
+        for c in str1 {
+            if *c != str2[prefix] || *c != str2[suffix] {
+                return false;
+            }
+            prefix += 1;
+            suffix += 1;
+        }
+
+        true
+    }
+}
\ No newline at end of file
diff --git a/src/week_385/problem2.rs b/src/week_385/problem2.rs
new file mode 100644
index 0000000..41018cf
--- /dev/null
+++ b/src/week_385/problem2.rs
@@ -0,0 +1,47 @@
+pub struct Solution {}
+
+use std::collections::HashSet;
+impl Solution {
+    pub fn longest_common_prefix(arr1: Vec<i32>, arr2: Vec<i32>) -> i32 {
+        let mut result = 0;
+        let mut set = HashSet::new();
+
+        for num in arr1 {
+            let mut num = num;
+
+            while num != 0 {
+                set.insert(num);
+                num = num / 10;
+            }
+        }
+
+        for num in arr2 {
+            let mut len = 0;
+            let mut i = num;
+            while i != 0 {
+                len += 1;
+                i = i / 10;
+            }
+            let mut i = num;
+            while i != 0 {
+                if set.contains(&i) {
+                    result = result.max(len);
+                }
+                len -= 1;
+                i = i / 10;
+            }
+        }
+
+        result
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_385_2() {
+        
+    }
+}
\ No newline at end of file
diff --git a/src/week_385/problem3.rs b/src/week_385/problem3.rs
new file mode 100644
index 0000000..ea0e268
--- /dev/null
+++ b/src/week_385/problem3.rs
@@ -0,0 +1,91 @@
+pub struct Solution {}
+
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn most_frequent_prime(mat: Vec<Vec<i32>>) -> i32 {
+        let direction = vec![
+            (0, 1),
+            (1, 0),
+            (-1, 0),
+            (0, -1),
+            (1, 1),
+            (-1, -1),
+            (1, -1),
+            (-1, 1),
+        ];
+
+        let mut result = HashMap::new();
+
+        let n = mat.len() as i32;
+        let m = mat[0].len() as i32;
+
+        for i in 0..n {
+            for j in 0..m {
+                for d in &direction {
+                    let mut num = 0;
+                    let mut step = 0;
+
+                    loop {
+                        let x = (i + d.0 * step);
+                        let y = (j + d.1 * step);
+                        step += 1;
+
+                        if x < 0 || x >= n || y < 0 || y >= m {
+                            break;
+                        }
+
+                        num = num * 10 + mat[x as usize][y as usize];
+
+                        if num > 10 {
+                            if let Some(entry) = result.get_mut(&num) {
+                                *entry += 1;
+                            } else if Solution::is_prime(num) {
+                                result.insert(num, 1);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        let (mut best, mut num) = (-1, 0);
+
+        for (key, value) in result {
+            if num < value || (num == value && key > best) {
+                best = key;
+                num = value;
+            }
+        }
+
+        best
+    }
+
+    fn is_prime(num: i32) -> bool {
+        let mut i = 2;
+        while i * i <= num {
+            if num % i == 0 {
+                return false;
+            }
+            i += 1;
+        }
+
+        true
+    }
+}
+
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_385_3() {
+        assert_eq!(
+            19,
+            Solution::most_frequent_prime(vec![vec![1, 1], vec![9, 9], vec![1, 1]])
+        );
+        assert_eq!(
+            29,
+            Solution::most_frequent_prime(vec![vec![2], vec![9], vec![6]])
+        );
+    }
+}