chore: Add course material

397/SolutionEx21/TimerSet.cpp

@@ -0,0 +1,23 @@
+#include "TimerSet.h"
+#include "Timer.h"
+#include <iostream>
+
+TimerSet::TimerSet() : timersInUse(0), previousTime(time(NULL)) {}
+
+void TimerSet::addATimer(Timer *t) { timers[timersInUse++] = t; }
+
+void TimerSet::pollAllTimers() {
+    std::time_t timeNow;
+    if (time(&timeNow) > previousTime) {
+        previousTime = timeNow;
+        for (int i = 0; i < timersInUse; ++i) {
+            timers[i]->tick();
+        }
+    }
+}
+
+TimerSet &TimerSet::Instance() {
+    // Meyer's Singleton implementation
+    static TimerSet pInstance;
+    return pInstance;
+}