set-practice

src/CommonElementsFinder.java

@@ -1,3 +1,4 @@
+import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -14,9 +15,19 @@ public class CommonElementsFinder {
      * @return a Set<Integer> containing the integers that are present in both arrays
      */
     public static Set<Integer> findCommonElements(int[] array1, int[] array2) {
-        // TODO
-        return null;
-    }
+        Set<Integer> numsArr1 = new HashSet<>();
+        for (int i = 0; i < array1.length; i++) {
+            numsArr1.add(array1[i]);
+        }
+        Set<Integer> commonNums = new HashSet<>();
+        for (int j = 0; j < array2.length; j++) {
+            if(numsArr1.contains(array2[j])) {
+                commonNums.add(array2[j]);
+            }
+        }
+        return commonNums;
+        }
+
 
 
     public static void main(String[] args) {

src/DuplicateRemover.java

@@ -1,4 +1,7 @@
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
 
 /**
  * The DuplicateRemover class provides a method to remove duplicate words
@@ -14,10 +17,24 @@ public class DuplicateRemover {
      * @return a sorted List<String> containing unique words from the input array
      */
     public static List<String> sortAndRemoveDuplicates(String[] words) {
-        // TODO
-        return null;
+
+        Set<String> unique = new TreeSet<>();
+
+        for (String word : words) {
+            unique.add(word);
+        }
+
+        List<String> wordList = new ArrayList();
+
+        for (String word : unique) {
+            wordList.add(word);
+        }
+
+        return wordList;
+
     }
 
+
     public static void main(String[] args) {
         String[] words = {"yes", "no", "maybe", "yes", "yes"};
         List<String> uniqueWords = sortAndRemoveDuplicates(words);

src/UniqueCharacterChecker.java

@@ -1,3 +1,5 @@
+import java.util.HashSet;
+import java.util.Set;
 /**
  * The UniqueCharacterChecker class provides a method to check if all characters
  * in a given word are unique.
@@ -11,11 +13,20 @@ public class UniqueCharacterChecker {
      * @return true if all characters in the word are unique; false otherwise
      */
     public static boolean hasUniqueCharacters(String word) {
-        // TODO: implement this!
-        // Requirement: This must run in O(n) time, where n is the number of characters in the word
-        // Hint: Stuck? Consider looking up "charAt" and seeing how it can help you
-        return false;
-    }
+
+        Set<Character> characters = new HashSet<>();
+
+        for (int i = 0; i < word.length(); i++) {
+            char currChar = word.charAt(i);
+            if (characters.contains(currChar)) {
+                return false;
+            }
+            characters.add(currChar);
+        }
+
+        return true;
+        }
+
 
     public static void main(String[] args) {
         String word1 = "hello";