Set practice

src/CommonElementsFinder.java

@@ -1,3 +1,4 @@
+import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -14,8 +15,26 @@ 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;
+        // Create a HashSet to store elements from the first array
+        HashSet<Integer> set1 = new HashSet<>();
+        // Iterate through the first array and add each element to the set
+        for(int num1 : array1) {
+            set1.add(num1);
+        }
+
+        // Create a HashSet to store common elements
+        HashSet<Integer> commonElements = new HashSet<>();
+        // Iterate through the second array
+        for(int num2 : array2){
+            // Check if the current element is in the first set
+            if(set1.contains(num2)) {
+                // If it is, add it to the common elements set
+                commonElements.add(num2);
+            }
+        }
+        // Return the set of common elements
+        return commonElements;
+
     }
 
 

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
@@ -14,8 +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;
+        //use tree set to store unique words by creatung a new TreeSet
+        Set<String> unique = new TreeSet<>();
+        //doing a for loop to iterate through the array
+        for(String word : words){
+            //adding each word to the set by using the add method
+            //if the word is already in the set, it will not be added again, meaning duplicates are removed
+            unique.add(word);
+        }
+
+        //convert the set to a list and in order to return it
+        List<String> wordList = new ArrayList<>();
+        //using a for loop to iterate through the set
+        for(String word : unique){
+            //adding each unique word to the list, which will be sorted automatically due to the nature of TreeSet
+            wordList.add(word);
+        }   
+
+        return wordList;
     }
 
     public static void main(String[] args) {

src/UniqueCharacterChecker.java

@@ -1,3 +1,5 @@
+import java.util.HashSet;
+
 /**
  * The UniqueCharacterChecker class provides a method to check if all characters
  * in a given word are unique.
@@ -12,9 +14,22 @@ public class UniqueCharacterChecker {
      */
     public static boolean hasUniqueCharacters(String word) {
         // TODO: implement this!
+        // Create a HashSet to store characters we've seen
+        HashSet<Character> uniqueChar = new HashSet<>();
+        // Iterate through each character in the word
+        for (int i = 0; i < word.length(); i++) {
+            char currentChar = word.charAt(i);
+            // Check if the character is already in the set
+            if (uniqueChar.contains(currentChar)) {
+                return false; // Duplicate found
+            }
+            // Add the character to the set
+            uniqueChar.add(currentChar);
+        }
         // 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;
+
+        return true; // All characters are unique
     }
 
     public static void main(String[] args) {
@@ -25,5 +40,7 @@ public static void main(String[] args) {
         System.out.println(word1 + " has unique characters: " + hasUniqueCharacters(word1));
         System.out.println(word2 + " has unique characters: " + hasUniqueCharacters(word2));
         System.out.println(word3 + " has unique characters: " + hasUniqueCharacters(word3));
+
+
     }
 }