Create solution.cpp

Author: wlgq2

1114.Print_In_Order/solution.cpp

@@ -0,0 +1,39 @@
+class Foo 
+{
+public:
+    Foo() 
+        :one_(false),
+        second_(false)
+    {
+
+    }
+
+    void first(function<void()> printFirst) 
+    {
+        unique_lock<mutex> lock(mutex_);
+        printFirst();
+        one_ = true;
+        condition_.notify_all();
+    }
+
+    void second(function<void()> printSecond) 
+    {
+        unique_lock<mutex> lock(mutex_);
+        condition_.wait(lock, [this]() { return one_; });
+        printSecond();
+        second_ = true;
+        condition_.notify_all();
+    }
+
+    void third(function<void()> printThird) 
+    {
+        unique_lock<mutex> lock(mutex_);
+        condition_.wait(lock, [this]() { return second_; });
+        printThird();
+    }
+private:
+    condition_variable condition_;
+    mutex mutex_;
+    bool one_;
+    bool second_;
+};