pre-merge commit

pom.xml

@@ -26,6 +26,11 @@
             <version>4.12</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.8.1</version>
+        </dependency>
     </dependencies>
 
 

src/main/java/rocks/zipcode/io/quiz4/collections/SimpleStringGroup.java

@@ -3,7 +3,7 @@ package rocks.zipcode.io.quiz4.collections;
 /**
  * @author leon on 11/12/2018.
  */
-public class SimpleStringGroup {
+public class SimpleStringGroup{
     public SimpleStringGroup() {
         throw new UnsupportedOperationException("Method not yet implemented");
     }

src/main/java/rocks/zipcode/io/quiz4/fundamentals/StringEvaluator.java

@@ -1,18 +1,53 @@
 package rocks.zipcode.io.quiz4.fundamentals;
 
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import org.apache.commons.lang3.StringUtils;
+
 /**
  * @author leon on 11/12/2018.
  */
 public class StringEvaluator {
     public static String[] getAllPrefixes(String string) {
-        return null;
+        List<String> pre = new ArrayList<>();
+        for (int i = 0; i <= string.length(); i++){
+            for (int j = i; j < string.length(); j++){
+                pre.add(string.substring(i, j+1));
+            }
+        }
+        pre = new ArrayList<String>(new LinkedHashSet<String>(pre));
+        return pre.toArray(new String[0]);
     }
 
     public static String[] getCommonPrefixes(String string1, String string2) {
-        return null;
+        String prefix = "";
+        int min = Math.min(string1.length(), string2.length());
+        for (int i = 0; i < min; i++){
+            if (string1.charAt(i) == string2.charAt(i)){
+                prefix = string1.substring(0, i);
+            }
+        }
+        return new String[]{prefix};
     }
 
     public static String getLargestCommonPrefix(String string1, String string2) {
-        return null;
+        int start = 0;
+        int max = 0;
+        for (int i = 0; i < string1.length(); i++){
+            for (int j = 0; j < string2.length(); j++){
+                int x = 0;
+                while (string1.charAt(i + x) == string2.charAt(j + x)){
+                    x++;
+                    if (((i + x) >= string1.length()) || ((j + x) >= string2.length()))
+                        break;
+                }
+                if (x > max){
+                    max = x;
+                    start = i;
+                }
+            }
+        }
+        return string1.substring(start, (start + max));
     }
 }

src/main/java/rocks/zipcode/io/quiz4/generics/GenericUtils.java

@@ -1,15 +1,29 @@
 package rocks.zipcode.io.quiz4.generics;
 
-import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.*;
 
 /**
  * @author leon on 11/12/2018.
  */
 public class GenericUtils {
     public static <_ extends Comparable> Iterable<? extends Iterable<_>> powerSet(Set<_> originalSet) {
-        return null;
+        Set<Set<_>> sets = new HashSet<Set<_>>();
+        if (originalSet.isEmpty()){
+            sets.add(new HashSet<_>());
+            return sets;
+        }
+        List<_> list = new ArrayList<_>(originalSet);
+        _ head = list.get(0);
+        Set<_> rest = new HashSet<_>(list.subList(1, list.size()));
+        for (Iterable<_> set : powerSet(rest)){
+            Set<_> newSet = new HashSet<_>();
+            newSet.add(head);
+            newSet.addAll((Collection<? extends _>) set);
+            sets.add(newSet);
+            sets.add((Set<_>) set);
+        }
+
+        return sets;
     }
 
     public static <_ extends Comparable> Iterable<? extends Iterable<_>> powerSet(_... originalSet) {

src/main/java/rocks/zipcode/io/quiz4/objectorientation/StringEvaluatorObject.java

@@ -1,5 +1,7 @@
 package rocks.zipcode.io.quiz4.objectorientation;
 
+import org.apache.commons.lang3.StringUtils;
+
 import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -33,6 +35,6 @@ public class StringEvaluatorObject {
     }
 
     public String getLargestCommonPrefix(String secondInput) {
-        return null;
+       return null;
     }
 }