feat: solved leet code problems for Zion Buchanan lesson 11 hw

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

@@ -1,22 +1,34 @@
 package com.codedifferently.lesson11;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class Lesson11 {
-
   /**
    * Provide the solution to LeetCode 1929 here:
    * 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;
+    var results = new ArrayList<Integer>();
+    for (int i = 0; i < words.length; i++) {
+      if (words[i].indexOf(x) > -1) {
+        results.add(i);
+      }
+    }
+    return results;
   }
-}
+}