refactor: ShortestCommonSuperSequenceLength (TheAlgorithms#5394)

alxkm · web-flow · commit b70f077343a4 · 2024-08-26T11:50:12.000+03:00
diff --git a/src/main/java/com/thealgorithms/dynamicprogramming/ShortestCommonSupersequenceLength.java b/src/main/java/com/thealgorithms/dynamicprogramming/ShortestCommonSupersequenceLength.java
@@ -1,12 +1,23 @@
 package com.thealgorithms.dynamicprogramming;
 
-// Java program to find length of the shortest supersequence
-final class ShortestSuperSequence {
-    private ShortestSuperSequence() {
+/**
+ * Class that provides methods to calculate the length of the shortest
+ * supersequence of two given strings. The shortest supersequence is the smallest string
+ * that contains both given strings as subsequences.
+ */
+final class ShortestCommonSuperSequenceLength {
+    private ShortestCommonSuperSequenceLength() {
     }
 
-    // Function to find length of the
-    // shortest supersequence of x and y.
+    /**
+     * Finds the length of the shortest supersequence of two given strings.
+     * The shortest supersequence is defined as the smallest string that contains both
+     * given strings as subsequences.
+     *
+     * @param x The first input string.
+     * @param y The second input string.
+     * @return The length of the shortest supersequence of the two strings.
+     */
     static int shortestSuperSequence(String x, String y) {
         int m = x.length();
         int n = y.length();
@@ -16,11 +27,20 @@ static int shortestSuperSequence(String x, String y) {
 
         // Result is sum of input string
         // lengths - length of lcs
-        return (m + n - l);
+        return m + n - l;
     }
 
-    // Returns length of LCS
-    // for x[0..m - 1], y[0..n - 1]
+    /**
+     * Calculates the length of the longest common subsequence (LCS) between two strings.
+     * The LCS is the longest sequence that can be derived from both strings by deleting some
+     * (or none) of the characters without changing the order of the remaining characters.
+     *
+     * @param x The first input string.
+     * @param y The second input string.
+     * @param m The length of the first input string.
+     * @param n The length of the second input string.
+     * @return The length of the longest common subsequence of the two strings.
+     */
     static int lcs(String x, String y, int m, int n) {
         int[][] lN = new int[m + 1][n + 1];
         int i;
@@ -46,13 +66,4 @@ static int lcs(String x, String y, int m, int n) {
         // for x[0..n - 1] and y[0..m - 1]
         return lN[m][n];
     }
-
-    // Driver code
-    public static void main(String[] args) {
-        String x = "AGGTAB";
-        String y = "GXTXAYB";
-
-        System.out.println("Length of the shortest "
-            + "supersequence is " + shortestSuperSequence(x, y));
-    }
 }
diff --git a/src/test/java/com/thealgorithms/dynamicprogramming/ShortestCommonSuperSequenceLengthTest.java b/src/test/java/com/thealgorithms/dynamicprogramming/ShortestCommonSuperSequenceLengthTest.java
@@ -0,0 +1,14 @@
+package com.thealgorithms.dynamicprogramming;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+public class ShortestCommonSuperSequenceLengthTest {
+    @ParameterizedTest
+    @CsvSource({"AGGTAB, GXTXAYB, 9", "ABC, ABC, 3", "ABC, DEF, 6", "'', ABC, 3", "ABCD, AB, 4", "ABC, BCD, 4", "A, B, 2"})
+    void testShortestSuperSequence(String input1, String input2, int expected) {
+        assertEquals(expected, ShortestCommonSuperSequenceLength.shortestSuperSequence(input1, input2));
+    }
+}
