resolve Checkstyle errors (constructor + imports)

Author: DenizAltunkapan

src/main/java/com/thealgorithms/graph/TravelingSalesman.java

@@ -10,8 +10,12 @@
  * For more information, see <a href="https://en.wikipedia.org/wiki/Travelling_salesman_problem">Wikipedia</a>.
  * @author  <a href="https://github.com/DenizAltunkapan">Deniz Altunkapan</a>
  */
+
 public class TravelingSalesman {
 
+    // Private constructor to prevent instantiation
+    private TravelingSalesman() {}
+
     /**
      * Solves the Traveling Salesman Problem (TSP) using brute-force approach.
      * This method generates all possible permutations of cities, calculates the total distance for each route, and returns the shortest distance found.

src/test/java/com/thealgorithms/graph/TravelingSalesmanTest.java

@@ -1,7 +1,6 @@
 package com.thealgorithms.graph;
 
-import static org.junit.jupiter.api.Assertions.*;
-
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.Test;
 
 public class TravelingSalesmanTest {