Fix checkstyle errors for ZAlgorithm

Author: Utkarsh-patel26

src/main/java/com/thealgorithms/strings/ZAlgorithm.java

@@ -1,35 +1,47 @@
 /*
  * https://en.wikipedia.org/wiki/Z-algorithm
  */
-
 package com.thealgorithms.strings;
 
-public class ZAlgorithm {
+public final class ZAlgorithm {
+
+    private ZAlgorithm() {
+        throw new UnsupportedOperationException("Utility class");
+    }
 
     public static int[] zFunction(String s) {
         int n = s.length();
         int[] z = new int[n];
-        int l = 0, r = 0;
+        int l = 0;
+        int r = 0;
+
         for (int i = 1; i < n; i++) {
-            if (i <= r)
+            if (i <= r) {
                 z[i] = Math.min(r - i + 1, z[i - l]);
-            while (i + z[i] < n && s.charAt(z[i]) == s.charAt(i + z[i]))
+            }
+
+            while (i + z[i] < n && s.charAt(z[i]) == s.charAt(i + z[i])) {
                 z[i]++;
+            }
+
             if (i + z[i] - 1 > r) {
                 l = i;
                 r = i + z[i] - 1;
             }
         }
+
         return z;
     }
 
     public static int search(String text, String pattern) {
         String s = pattern + "$" + text;
         int[] z = zFunction(s);
         int p = pattern.length();
+
         for (int i = 0; i < z.length; i++) {
-            if (z[i] == p)
+            if (z[i] == p) {
                 return i - p - 1;
+            }
         }
         return -1;
     }

src/test/java/com/thealgorithms/strings/ZAlgorithmTest.java

@@ -1,9 +1,8 @@
-/*
- * https://en.wikipedia.org/wiki/Z-algorithm
- */
 package com.thealgorithms.strings;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import org.junit.jupiter.api.Test;
 
 public class ZAlgorithmTest {