Feat: adds Shawn Dunsmore Lesson11 java.

Author: Djtheman1

lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java

@@ -1,5 +1,5 @@
 package com.codedifferently.lesson11;
-
+import java.util.ArrayList;
 import java.util.List;
 
 public class Lesson11 {
@@ -9,14 +9,32 @@ public class Lesson11 {
    * https://leetcode.com/problems/concatenation-of-array
    */
   public int[] getConcatenation(int[] nums) {
-    return null;
-  }
+        int n = nums.length; 
+        int[] ans = new int[2 * n];
+        
+        
+        for (int i = 0; i < n; i++) {
+            ans[i] = nums[i];         
+            ans[i + n] = nums[i];     
+        }
+      
+        return ans; 
+}
+
 
   /**
    * Provide the solution to LeetCode 2942 here:
    * https://leetcode.com/problems/find-words-containing-character/
    */
-  public List<Integer> findWordsContaining(String[] words, char x) {
-    return null;
-  }
+   public List<Integer> findWordsContaining(String[] words, char x) {
+        List<Integer> indices = new ArrayList<>(); 
+
+        for (int i = 0; i < words.length; i++) {
+            if (words[i].indexOf(x) != -1) {
+                indices.add(i); 
+            }
+        }
+
+        return indices; 
+    }
 }