support bazel complie this project and format code.

basic_content/abstract/interesting_facts4.cpp

@@ -6,30 +6,29 @@
  * @date 2019-07-20
  */
 
-#include<iostream> 
-using namespace std; 
+#include <iostream>
+using namespace std;
 
-// An abstract class with constructor 
-class Base 
-{ 
-    protected: 
-        int x; 
-    public: 
-        virtual void fun() = 0; 
-        Base(int i) { x = i; } 
-}; 
+// An abstract class with constructor
+class Base {
+protected:
+  int x;
 
-class Derived: public Base 
-{ 
-    int y; 
-    public: 
-    Derived(int i, int j):Base(i) { y = j; } 
-    void fun() { cout << "x = " << x << ", y = " << y; } 
-}; 
+public:
+  virtual void fun() = 0;
+  Base(int i) { x = i; }
+};
 
-int main(void) 
-{ 
-    Derived d(4, 5); 
-    d.fun(); 
-    return 0; 
-} 
+class Derived : public Base {
+  int y;
+
+public:
+  Derived(int i, int j) : Base(i) { y = j; }
+  void fun() { cout << "x = " << x << ", y = " << y; }
+};
+
+int main(void) {
+  Derived d(4, 5);
+  d.fun();
+  return 0;
+}