diff --git a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README.md b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README.md
index 1de9e92ed8677..f5b167c632c59 100644
--- a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README.md	
+++ b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README.md	
@@ -217,6 +217,51 @@ var longestSubarray = function (nums) {
 };
 ```
 
+#### C#
+
+```cs
+public class Solution {
+    public int LongestSubarray(int[] nums) {
+        int mx = nums.Max();
+        int ans = 0, cnt = 0;
+        foreach (int x in nums) {
+            if (x == mx) {
+                ans = Math.Max(ans, ++cnt);
+            } else {
+                cnt = 0;
+            }
+        }
+        return ans;
+    }
+}
+```
+
+#### PHP
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function longestSubarray($nums) {
+        $mx = max($nums);
+        $ans = 0;
+        $cnt = 0;
+
+        foreach ($nums as $x) {
+            if ($x == $mx) {
+                $ans = max($ans, ++$cnt);
+            } else {
+                $cnt = 0;
+            }
+        }
+
+        return $ans;
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README_EN.md b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README_EN.md
index c95729b44a910..e6d663d5fd01b 100644
--- a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README_EN.md	
+++ b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/README_EN.md	
@@ -215,6 +215,51 @@ var longestSubarray = function (nums) {
 };
 ```
 
+#### C#
+
+```cs
+public class Solution {
+    public int LongestSubarray(int[] nums) {
+        int mx = nums.Max();
+        int ans = 0, cnt = 0;
+        foreach (int x in nums) {
+            if (x == mx) {
+                ans = Math.Max(ans, ++cnt);
+            } else {
+                cnt = 0;
+            }
+        }
+        return ans;
+    }
+}
+```
+
+#### PHP
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function longestSubarray($nums) {
+        $mx = max($nums);
+        $ans = 0;
+        $cnt = 0;
+
+        foreach ($nums as $x) {
+            if ($x == $mx) {
+                $ans = max($ans, ++$cnt);
+            } else {
+                $cnt = 0;
+            }
+        }
+
+        return $ans;
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.cs b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.cs
new file mode 100644
index 0000000000000..43ec08525037c
--- /dev/null
+++ b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.cs	
@@ -0,0 +1,14 @@
+public class Solution {
+    public int LongestSubarray(int[] nums) {
+        int mx = nums.Max();
+        int ans = 0, cnt = 0;
+        foreach (int x in nums) {
+            if (x == mx) {
+                ans = Math.Max(ans, ++cnt);
+            } else {
+                cnt = 0;
+            }
+        }
+        return ans;
+    }
+}
diff --git a/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.php b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.php
new file mode 100644
index 0000000000000..390d95d2acbd8
--- /dev/null
+++ b/solution/2400-2499/2419.Longest Subarray With Maximum Bitwise AND/Solution.php	
@@ -0,0 +1,21 @@
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function longestSubarray($nums) {
+        $mx = max($nums);
+        $ans = 0;
+        $cnt = 0;
+
+        foreach ($nums as $x) {
+            if ($x == $mx) {
+                $ans = max($ans, ++$cnt);
+            } else {
+                $cnt = 0;
+            }
+        }
+
+        return $ans;
+    }
+}
\ No newline at end of file