feat: adds lesson_11-Kimberlee's leetcode problems

Author: haldanek

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

@@ -9,14 +9,30 @@ 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;
+          
+    List<Integer> output = new ArrayList<>();
+
+      for (int i = 0; i < words.length; i++) {
+
+        if (words[i].indexOf(x) != -1) {
+            output.add(i);
+        }   
+    }
+     return output;
   }
 }