support bazel complie this project and format code.

practical_exercises/10_day_practice/day9/exception/4.cpp

@@ -0,0 +1,23 @@
+#include <iostream>
+using namespace std;
+void temperature(int t) {
+
+  if (t == 100)
+    throw "沸点！";
+  else if (t == 0)
+    throw "冰点！";
+  else {
+    cout << "temperatore=" << t << endl;
+  }
+}
+int main() {
+  try {
+    temperature(0);   // L1
+    temperature(10);  // L2
+    temperature(100); // L3
+  } catch (char const *s) {
+    cout << s << endl;
+  }
+  
+  return 0;
+}