@@ -0,0 +1,34 @@
+package TIL;
+
+public class Extends {
+    public static void main(String[] args) {
+        Super s = new child();
+        s.sayA();
+        s.sayB();
+    }
+}
+
+class Super{
+    public  void sayA() {
+        System.out.println("A");
+        sayB();
+    }
+
+    public void sayB(){
+        System.out.println("B");
+        this.sayB();
+
+    }
+}
+
+class child extends Super{
+    public void sayA(){
+        super.sayB();
+        System.out.println("a");
+
+    }
+
+    public void sayB(){
+        System.out.println("b");
+    }
+}
@@ -17,5 +17,12 @@ public static void main(String[] args) throws IOException {
                 }else System.out.println(pq.poll());
             }else pq.offer(value);
         }
+
+//        int a= A();
     }
+
+//    public int A(){
+//        return 3;
+
+//    }
 }
@@ -1,10 +1,13 @@
 package TIL;
 
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
 
 public class hi {
     public static void main(String[] args) {
-        Set<Integer> set = new HashSet<>();
+        List<Integer> list = new ArrayList<>();
+
+
+        Collections.sort(list, (o1, o2)-> o2-o1);
+
     }
 }
Original file line number	Diff line number	Diff line change
`@@ -17,5 +17,12 @@ public static void main(String[] args) throws IOException {`
`17`	`17`	`}else System.out.println(pq.poll());`
`18`	`18`	`}else pq.offer(value);`
`19`	`19`	`}`
	`20`	`+`
	`21`	`+// int a= A();`
`20`	`22`	`}`
	`23`	`+`
	`24`	`+// public int A(){`
	`25`	`+// return 3;`
	`26`	`+`
	`27`	`+// }`
`21`	`28`	`}`