Create fizz-buzz-multithreaded.cpp

Author: kamyu104

C++/fizz-buzz-multithreaded.cpp

@@ -0,0 +1,74 @@
+// Time:  O(n)
+// Space: O(1)
+
+class FizzBuzz {
+public:
+    FizzBuzz(int n) : n_(n) {
+    }
+
+    // printFizz() outputs "fizz".
+    void fizz(function<void()> printFizz) {
+        for (int i = 1; i <= n_; ++i) {
+            {
+                unique_lock<mutex> l(m_);
+                wait_.wait(l, [this]() { return curr_ % 4 == 0; });
+                ++curr_;
+                if (i % 3 == 0 && i % 5 != 0) {
+                    printFizz();
+                }
+            }
+            wait_.notify_all();
+        }
+    }
+
+    // printBuzz() outputs "buzz".
+    void buzz(function<void()> printBuzz) {
+        for (int i = 1; i <= n_; ++i) {
+            {
+                unique_lock<mutex> l(m_);
+                wait_.wait(l, [this]() { return curr_ % 4 == 1; });
+                ++curr_;
+                if (i % 3 != 0 && i % 5 == 0) {
+                    printBuzz();
+                }
+            }
+            wait_.notify_all();
+        }
+    }
+
+    // printFizzBuzz() outputs "fizzbuzz".
+	void fizzbuzz(function<void()> printFizzBuzz) {
+        for (int i = 1; i <= n_; ++i) {
+            {
+                unique_lock<mutex> l(m_);
+                wait_.wait(l, [this]() { return curr_ % 4 == 2; });
+                ++curr_;
+                if (i % 3 == 0 && i % 5 == 0) {
+                    printFizzBuzz();
+                }
+            }
+            wait_.notify_all();
+        }
+    }
+
+    // printNumber(x) outputs "x", where x is an integer.
+    void number(function<void(int)> printNumber) {
+        for (int i = 1; i <= n_; ++i) {
+            {
+                unique_lock<mutex> l(m_);
+                wait_.wait(l, [this]() { return curr_ % 4 == 3; });
+                ++curr_;
+                if (i % 3 != 0 && i % 5 != 0) {
+                    printNumber(i);
+                }
+            }
+            wait_.notify_all();
+        }
+    }
+
+private:
+    int n_;
+    int curr_ = 0;
+    mutex m_;
+    condition_variable wait_;
+};