Create traffic-light-controlled-intersection.cpp

Author: kamyu104

C++/traffic-light-controlled-intersection.cpp

@@ -0,0 +1,29 @@
+// Time:  O(n)
+// Space: O(1)
+
+class TrafficLight {
+public:
+    TrafficLight()
+     : light_{1} {
+        
+    }
+
+    void carArrived(
+        int carId,                   // ID of the car
+        int roadId,                  // ID of the road the car travels on. Can be 1 (road A) or 2 (road B)
+        int direction,               // Direction of the car
+        function<void()> turnGreen,  // Use turnGreen() to turn light to green on current road
+        function<void()> crossCar    // Use crossCar() to make car cross the intersection
+    ) {
+        unique_lock<mutex> lock{m_};
+        if (light_ != roadId) {
+            light_ = roadId;
+			turnGreen();
+		}
+        crossCar();
+    }
+
+private:
+    mutex m_;
+    int light_;
+};