Update directory

Author: BugWriter007

DIRECTORY.md

@@ -204,6 +204,7 @@
               * [RotateSinglyLinkedLists](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/RotateSinglyLinkedLists.java)
               * [SearchSinglyLinkedListRecursion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/SearchSinglyLinkedListRecursion.java)
               * [SinglyLinkedList](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/SinglyLinkedList.java)
+              * [SinglyLinkedListNode](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/SinglyLinkedListNode.java)
               * [SkipList](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/SkipList.java)
               * [SortedLinkedList](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/lists/SortedLinkedList.java)
             * [Node](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/Node.java)
@@ -337,6 +338,7 @@
           * graph
             * [ConstrainedShortestPath](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/graph/ConstrainedShortestPath.java)
             * [StronglyConnectedComponentOptimized](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/graph/StronglyConnectedComponentOptimized.java)
+            * [TravelingSalesman](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/graph/TravelingSalesman.java)
           * greedyalgorithms
             * [ActivitySelection](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/ActivitySelection.java)
             * [BandwidthAllocation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/greedyalgorithms/BandwidthAllocation.java)
@@ -488,6 +490,7 @@
             * [MirrorOfMatrix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/matrix/MirrorOfMatrix.java)
             * [PrintAMatrixInSpiralOrder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/matrix/PrintAMatrixInSpiralOrder.java)
             * [RotateMatrixBy90Degrees](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/matrix/RotateMatrixBy90Degrees.java)
+            * [SolveSystem](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/matrix/SolveSystem.java)
             * utils
               * [MatrixUtil](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/matrix/utils/MatrixUtil.java)
           * misc
@@ -552,6 +555,8 @@
             * [Sudoku](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/puzzlesandgames/Sudoku.java)
             * [TowerOfHanoi](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/puzzlesandgames/TowerOfHanoi.java)
             * [WordBoggle](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/puzzlesandgames/WordBoggle.java)
+          * randomized
+            * [ReservoirSampling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/randomized/ReservoirSampling.java)
           * recursion
             * [FibonacciSeries](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/recursion/FibonacciSeries.java)
             * [GenerateSubsets](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/recursion/GenerateSubsets.java)
@@ -1024,6 +1029,7 @@
           * graph
             * [ConstrainedShortestPathTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/graph/ConstrainedShortestPathTest.java)
             * [StronglyConnectedComponentOptimizedTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/graph/StronglyConnectedComponentOptimizedTest.java)
+            * [TravelingSalesmanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/graph/TravelingSalesmanTest.java)
           * greedyalgorithms
             * [ActivitySelectionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/ActivitySelectionTest.java)
             * [BandwidthAllocationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/greedyalgorithms/BandwidthAllocationTest.java)
@@ -1159,6 +1165,7 @@
             * [MatrixUtilTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/matrix/MatrixUtilTest.java)
             * [MedianOfMatrixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/matrix/MedianOfMatrixTest.java)
             * [MirrorOfMatrixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/matrix/MirrorOfMatrixTest.java)
+            * [SolveSystemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/matrix/SolveSystemTest.java)
             * [TestPrintMatrixInSpiralOrder](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/matrix/TestPrintMatrixInSpiralOrder.java)
           * misc
             * [ColorContrastRatioTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/ColorContrastRatioTest.java)
@@ -1205,6 +1212,8 @@
             * [SudokuTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/puzzlesandgames/SudokuTest.java)
             * [TowerOfHanoiTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/puzzlesandgames/TowerOfHanoiTest.java)
             * [WordBoggleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/puzzlesandgames/WordBoggleTest.java)
+          * randomized
+            * [ReservoirSamplingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/randomized/ReservoirSamplingTest.java)
           * recursion
             * [FibonacciSeriesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/recursion/FibonacciSeriesTest.java)
             * [GenerateSubsetsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/recursion/GenerateSubsetsTest.java)