update readme

Author: yennanliu

README.md

@@ -186,7 +186,7 @@
 ||Merge sort|[merge_sort_topdown.py](./algorithm/python/merge_sort_topdown.py), [mergesort_bottomup.py](./algorithm/python/merge_sort_bottomup.py), [MergeSortTopDown.java](./leetcode_java/src/main/java/AlgorithmJava/MergeSortTopDown.java), [SQL](./algorithm/sql/Mergesort.sql) | | | `Best : O(N Log N), Avg : O(N Log N), Worst : O(N Log N)` | O(N)| OK* (2)| 
 ||Pancake sort| [Python](./algorithm/python/pancake_sort.py) | | | | | AGAIN| 
 ||Selection sort| [Python](./algorithm/python/selection_sort.py), [JS](./algorithm/js/selection_sort.js) | | | | |  AGAIN| 
-||Topological sort| [Python](./algorithm/python/topological_sort.py), [Java](./leetcode_java/src/main/java/AlgorithmJava/TopologicalSort.java) | | Topological Sort is a algorithm can find "ordering" on an "order dependency" graph | | | AGAIN| 
+||Topological sort| [Python](./algorithm/python/topological_sort.py), [Java](./leetcode_java/src/main/java/AlgorithmJava/TopologicalSort.java), [Java V2](./leetcode_java/src/main/java/AlgorithmJava/TopologicalSortV2.java)  | | Topological Sort is a algorithm can find "ordering" on an "order dependency" graph | | | AGAIN| 
 ||md5 | [Python](./algorithm/python/md5.py) | | | | | AGAIN| 
 ||Union Find | [Python 1](./algorithm/python/union_find.py), [Python 2](./algorithm/python/union_find_if_cyclic.py), [Java 1](./leetcode_java/src/main/java/AlgorithmJava/UnionFind.java) | | | AGAIN| 
 ||Dynamic programming|[JS 1](./algorithm/js/dp_demo_1.js), [fibonacci_dp JS](./algorithm/js/fibonacci_dp.js) | | | | | AGAIN|

leetcode_java/src/main/java/AlgorithmJava/TopologicalSort.java

@@ -172,7 +172,8 @@ public static void main(String[] args) {
         TopologicalSort topoSort = new TopologicalSort();
         int numCourses = 4;
         // Directed Acyclic Graph (DAG) where each directed edge u -> v means that u comes before v.
-        int[][] prerequisites = {{1, 0}, {2, 0}, {3, 1}, {3, 2}};
+        //int[][] prerequisites = {{1, 0}, {2, 0}, {3, 1}, {3, 2}};
+        int[][] prerequisites = {{1, 0}, {3, 1}, {2, 0}, {3, 2}};
 
         int[] result = topoSort.topologicalSort(numCourses, prerequisites);
         System.out.println("Topological Order: " + Arrays.toString(result));