support bazel complie this project and format code.

practical_exercises/key_exercises/array.cpp

@@ -0,0 +1,14 @@
+/* 数组.cpp */
+#include <cstring>
+#include <iostream>
+
+int main() {
+
+  char *sPtr;
+  const char *s = "hello";
+  sPtr = new char[strlen(s) + 1];
+  strncpy(sPtr, s, strlen(s));
+  std::cout << sPtr << std::endl;
+  delete sPtr;
+  return 0;
+}