add

Author: yennj12

leetcode_java/src/main/java/dev/Sorting/HashMapSortTest.java

@@ -69,7 +69,7 @@ public void testSortMapWithValue(){
          * - The lambda expression is shorthand for an anonymous inner class that implements the compare method directly.
          *
          */
-        
+
 
         /** V1 : lambda expression  */
 //        Collections.sort(keyList, (x,y) -> {

leetcode_java/src/main/java/dev/Sorting/ListSortTest.java

@@ -1,4 +1,42 @@
 package dev.Sorting;
 
+import org.junit.Test;
+
+import java.util.*;
+
 public class ListSortTest {
+
+    @Test
+    public void testSortListWithVal_1(){
+
+        List<Integer> list = new ArrayList<>();
+        list.add(5);
+        list.add(99);
+        list.add(1);
+        list.add(-3);
+
+        System.out.println(">>> (before) list = " + list);
+        
+        // V1: lambda
+        Collections.sort(list, (x,y) -> {
+            int diff = y - x;
+            return diff;
+        });
+//
+//        // V2: Comparator.compare
+//        Collections.sort(list, new Comparator<Integer>(){
+//            @Override
+//            public int compare(Integer o1, Integer o2) {
+//                //int diff = o1 - o2;  // smaller first (increasing order)
+//                int diff = o2 - o1; // bigger first, (decreasing order)
+////                if(diff == 0){
+////                    return
+////                }
+//                return diff;
+//            }
+//        });
+
+        System.out.println(">>> (after) list = " + list);
+
+    }
 }