support bazel complie this project and format code.

practical_exercises/10_day_practice/day4/clock/BUILD

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+# please run `bazel run //practical_exercises/10_day_practice/day4/clock:operator`
+# please run `bazel run //practical_exercises/10_day_practice/day4/clock:operator_plus`
+
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "operator",
+    srcs = ["operator.cpp"],
+)
+cc_binary(
+    name = "operator_plus",
+    srcs = ["operator_plus.cpp"],
+)

practical_exercises/10_day_practice/day4/clock/operator.cpp

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+/* 重载()的时钟.cpp */
+#include <iostream>
+using namespace std;
+class Time {
+private:
+  int hh, mm, ss;
+
+public:
+  Time(int h = 0, int m = 0, int s = 0) : hh(h), mm(m), ss(s) {}
+  void operator()(int h, int m, int s) {
+    hh = h;
+    mm = m;
+    ss = s;
+  }
+  void ShowTime() { cout << hh << ":" << mm << ":" << ss << endl; }
+};
+int main() {
+  Time t1(12, 10, 11);
+  t1.ShowTime();
+  t1.operator()(23, 20, 34);
+  t1.ShowTime();
+  t1(10, 10, 10);
+  t1.ShowTime();
+  
+}

practical_exercises/10_day_practice/day4/clock/operator_plus.cpp

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+/* 重载++的时钟.cpp */
+/*
+设计一个时钟类，能够记录时、分、秒，重载它的++运算符，每执行一次++运算，加时1秒，但要使计时过程能够自动进位。
+*/
+#include <iostream>
+using namespace std;
+class Time {
+public:
+  Time(int h = 0, int m = 0, int s = 0) {
+    hour = h;
+    minute = m;
+    second = s;
+  }
+  Time operator++();
+  Time operator++(int);
+  void showTime() {
+    cout << "当前时间为：" << hour << ":" << minute << ":" << second << endl;
+  }
+
+private:
+  int hour, minute, second;
+};
+Time Time::operator++(int n) {
+  Time tmp = *this;
+  ++(*this);
+  return tmp;
+}
+Time Time::operator++() {
+  ++second;
+  if (second == 60) {
+    second = 0;
+    ++minute;
+    if (minute == 60) {
+      minute = 0;
+      hour++;
+      if (hour == 24) {
+        hour = 0;
+      }
+    }
+  }
+  return *this;
+}
+
+int main(int argc, char const *argv[]) {
+  Time t(23, 59, 59);
+  ++t;
+  t.showTime();
+  (t++).showTime();
+  t.showTime();
+  
+  return 0;
+}