feat(hackerrank): IBM HackerRank Assessment 2026

src/main/java/com/shortthirdman/primekit/coderbyte/PatternAnalyzer.java

@@ -6,7 +6,6 @@
 import com.shortthirdman.primekit.core.strategy.PremiumTaxCalculation;
 import com.shortthirdman.primekit.core.strategy.StandardTaxCalculation;
 import com.shortthirdman.primekit.core.strategy.TaxCalculationStrategy;
-import lombok.RequiredArgsConstructor;
 
 import java.util.Objects;
 

src/main/java/com/shortthirdman/primekit/hackerrank/SpamTextClassifier.java

@@ -0,0 +1,99 @@
+package com.shortthirdman.primekit.hackerrank;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Spam Text Classifier:
+ *   A text is "spam" if it contains ≥ 2 occurrences of words from spamWords (case-insensitive, exact matches). Otherwise, return "not_spam".
+ * @author ShortThirdMan
+ * @since 1.1.2
+ */
+public class SpamTextClassifier {
+
+    /**
+     * Classifies a list of texts as "SPAM" or "NOT SPAM" based on the presence of spam words.
+     * @param texts the array of texts to classify as spam or not spam
+     * @param spamWords an array of words that are considered spam indicators
+     * @return a list of strings, where each element is "SPAM" if the corresponding text contains any of the spam words, and "NOT SPAM" otherwise
+     */
+    public List<String> classifyTexts(List<String> texts, List<String> spamWords) {
+        if (texts == null || spamWords == null) {
+            throw new NullPointerException("texts and spam words cannot be null");
+        }
+
+        if (texts.isEmpty()) {
+            return List.of();
+        }
+
+        Set<String> spamSet = new HashSet<>();
+        for (String word : spamWords) {
+            spamSet.add(word.toLowerCase());
+        }
+
+        List<String> result = new ArrayList<>(texts.size());
+
+        for (String text : texts) {
+
+            int spamCount = 0;
+
+            // Split words by a single space
+            String[] words = text.split(" ");
+
+            for (String word : words) {
+                if (spamSet.contains(word.toLowerCase())) {
+                    spamCount++;
+
+                    // Early exit optimization
+                    if (spamCount >= 2) {
+                        result.add("spam");
+                        break;
+                    }
+                }
+            }
+
+            if (spamCount < 2) {
+                result.add("not_spam");
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * Classifies a list of texts as "SPAM" or "NOT SPAM" based on the presence of spam words.
+     * @param texts the list of texts to classify
+     * @param spamWords the list of spam words to check against
+     * @return a list of classifications ("spam" or "not_spam") for each text in the input list,
+     * processed in parallel for improved performance
+     */
+    public List<String> classifyTextStream(List<String> texts, List<String> spamWords) {
+        if (texts == null || spamWords == null) {
+            throw new NullPointerException("texts and spam words cannot be null");
+        }
+
+        if (texts.isEmpty()) {
+            return List.of();
+        }
+
+        Set<String> spamSet = spamWords.stream()
+                .map(String::toLowerCase)
+                .collect(Collectors.toSet());
+
+        return texts.parallelStream()
+                .map(text -> {
+                    long spamCount = Arrays.stream(text.split(" "))
+                            .map(String::toLowerCase)
+                            .filter(spamSet::contains)
+                            .limit(2)
+                            .count();
+
+                    return spamCount >= 2 ? "spam" : "not_spam";
+                })
+                .toList();
+    }
+}