Renaming class Subsequence to SubsequenceFinder. Refactored test to Parametrized test. Fixed input parameter as final.

Author: alxkm

src/main/java/com/thealgorithms/backtracking/Subsequence.java renamed to src/main/java/com/thealgorithms/backtracking/SubsequenceFinder.java

@@ -6,8 +6,8 @@
 /**
  * Class generates all subsequences for a given list of elements using backtracking
  */
-public final class Subsequence {
-    private Subsequence() {
+public final class SubsequenceFinder {
+    private SubsequenceFinder() {
     }
 
     /**
@@ -39,7 +39,7 @@ public static <T> List<List<T>> generateAllSubsequences(List<T> sequence) {
      * @param allSubSequences contains all sequences
      * @param <T> the type of elements which we generate
      */
-    private static <T> void backtrack(List<T> sequence, List<T> currentSubsequence, int index, List<List<T>> allSubSequences) {
+    private static <T> void backtrack(List<T> sequence, List<T> currentSubsequence, final int index, List<List<T>> allSubSequences) {
         if (index == sequence.size()) {
             allSubSequences.add(new ArrayList<>(currentSubsequence));
             return;

src/test/java/com/thealgorithms/backtracking/SubsequenceTest.java

@@ -1,39 +1,32 @@
 package com.thealgorithms.backtracking;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertIterableEquals;
 
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
 import java.util.ArrayList;
 import java.util.List;
-import org.junit.jupiter.api.Test;
+import java.util.stream.Stream;
 
 public class SubsequenceTest {
 
-    @Test
-    void testNoElement() {
-        List<List<Object>> emptyResult = Subsequence.generateAllSubsequences(new ArrayList<>());
-        assertEquals(1, emptyResult.size());
-        assertEquals(0, emptyResult.get(0).size());
-    }
-
-    @Test
-    void testLengthOfTwo() {
-        List<List<Integer>> expected = List.of(List.of(), List.of(2), List.of(1), List.of(1, 2));
-        List<List<Object>> actual = Subsequence.generateAllSubsequences(List.of(1, 2));
-        assertIterableEquals(expected, actual);
+    @ParameterizedTest
+    @MethodSource("getSubsequenceTestData")
+    void testSubsequences(SubsequenceTestData testData) {
+        List<List<Object>> actual = SubsequenceFinder.generateAllSubsequences(testData.input());
+        assertIterableEquals(testData.expected(), actual);
     }
 
-    @Test
-    void testLengthOfThree() {
-        List<List<String>> expected = List.of(List.of(), List.of("C"), List.of("B"), List.of("B", "C"), List.of("A"), List.of("A", "C"), List.of("A", "B"), List.of("A", "B", "C"));
-        List<List<Object>> actual = Subsequence.generateAllSubsequences(List.of("A", "B", "C"));
-        assertIterableEquals(expected, actual);
+    static Stream<SubsequenceTestData> getSubsequenceTestData() {
+        return Stream.of(
+                new SubsequenceTestData(new ArrayList<>(), List.of(List.of())),
+                new SubsequenceTestData(List.of(1, 2), List.of(List.of(), List.of(2), List.of(1), List.of(1, 2))),
+                new SubsequenceTestData(List.of("A", "B", "C"), List.of(List.of(), List.of("C"), List.of("B"), List.of("B", "C"), List.of("A"), List.of("A", "C"), List.of("A", "B"), List.of("A", "B", "C"))),
+                new SubsequenceTestData(List.of(1, 2, 3), List.of(List.of(), List.of(3), List.of(2), List.of(2, 3), List.of(1), List.of(1, 3), List.of(1, 2), List.of(1, 2, 3)))
+        );
     }
 
-    @Test
-    void testLengthOfThreeInteger() {
-        List<List<Integer>> expected = List.of(List.of(), List.of(3), List.of(2), List.of(2, 3), List.of(1), List.of(1, 3), List.of(1, 2), List.of(1, 2, 3));
-        List<List<Object>> actual = Subsequence.generateAllSubsequences(List.of(1, 2, 3));
-        assertIterableEquals(expected, actual);
+    record SubsequenceTestData(List<Object> input, List<List<Object>> expected) {
     }
 }