diff --git a/cpp/filter.cpp b/cpp/filter.cpp
new file mode 100644
index 0000000..1a0dc10
--- /dev/null
+++ b/cpp/filter.cpp
@@ -0,0 +1,4 @@
+int smooth_sample(int current, int previous) {
+    if (current > previous) return (current + previous) / 2;
+    return current;
+}