diff --git a/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java b/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
index 248938a96..bccad5dc1 100644
--- a/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
+++ b/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
@@ -1,5 +1,6 @@
 package com.codedifferently.lesson11;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class Lesson11 {
@@ -9,7 +10,10 @@ public class Lesson11 {
    * https://leetcode.com/problems/concatenation-of-array
    */
   public int[] getConcatenation(int[] nums) {
-    return null;
+    int[] ans = new int[(nums.length + nums.length)];
+    System.arraycopy(nums, 0, ans, 0, nums.length);
+    System.arraycopy(nums, 0, ans, nums.length, nums.length);
+    return ans;
   }
 
   /**
@@ -17,6 +21,16 @@ public int[] getConcatenation(int[] nums) {
    * https://leetcode.com/problems/find-words-containing-character/
    */
   public List<Integer> findWordsContaining(String[] words, char x) {
-    return null;
+    List<Integer> num = new ArrayList<>();
+    for (var i = 0; i < words.length; i++) {
+      var word = String.valueOf(words[i]);
+      for (var j = 0; j < word.length(); j++) {
+        if (word.contains(String.valueOf(x))) {
+          num.add(i);
+          break;
+        }
+      }
+    }
+    return num;
   }
 }
diff --git a/lesson_11/arrays_ts/src/lesson11.ts b/lesson_11/arrays_ts/src/lesson11.ts
index 54af1ba03..5cd2f0e8b 100644
--- a/lesson_11/arrays_ts/src/lesson11.ts
+++ b/lesson_11/arrays_ts/src/lesson11.ts
@@ -3,7 +3,14 @@
  * https://leetcode.com/problems/concatenation-of-array
  */
 export function getConcatenation(nums: number[]): number[] {
-  return [];
+  const ans: number[] = [];
+  for (const num of nums) {
+    ans.push(num);
+  }
+  for (const num of nums) {
+    ans.push(num);
+  }
+  return ans;
 }
 
 /**
@@ -11,5 +18,13 @@ export function getConcatenation(nums: number[]): number[] {
  * https://leetcode.com/problems/find-words-containing-character/
  */
 export function findWordsContaining(words: string[], x: string): number[] {
-  return [];
+  const num: number[] = [];
+  for (const word of words) {
+    const wordArr = word.split('');
+    const containsX = wordArr.some((char) => x.includes(char));
+    if (containsX) {
+      num.push(words.indexOf(word));
+    }
+  }
+  return num;
 }