adding test.cpp

lectures/optimization/gprof/README.md

@@ -15,7 +15,7 @@ $ g++ -pg -o test test.cpp
 ```
 
 ## Example C++ Program
-Create a file `test.cpp` with the following code:
+Create a file [test.cpp](test.cpp) with the following code:
 ```cpp
 #include <iostream>
 

lectures/optimization/gprof/test.cpp

@@ -0,0 +1,25 @@
+#include <iostream>
+
+void heavyComputation() {
+    // The use of volatile prevents compiler optimizations that could remove the loops.
+    volatile long long sum = 0;
+    for (long long i = 0; i < 500000000; ++i) {
+        sum += i;  // Simple but expensive loop
+    }
+}
+
+void lightComputation() {
+    // The use of volatile prevents compiler optimizations that could remove the loops.
+    volatile int sum = 0;
+    for (int i = 0; i < 100000; ++i) {
+        sum += i;  // Lighter loop
+    }
+}
+
+int main() {
+    heavyComputation();  // Call heavy function once
+    for (int i = 0; i < 1000; ++i) {
+        lightComputation();  // Call light function many times
+    }
+    return 0;
+}