add missing header

Author: jmalkin

count/include/count_min_impl.hpp

@@ -20,14 +20,15 @@
 #ifndef COUNT_MIN_IMPL_HPP_
 #define COUNT_MIN_IMPL_HPP_
 
-#include "MurmurHash3.h"
-#include "count_min.hpp"
-#include "memory_operations.hpp"
-
+#include <algorithm>
 #include <iomanip>
 #include <random>
 #include <sstream>
 
+#include "MurmurHash3.h"
+#include "count_min.hpp"
+#include "memory_operations.hpp"
+
 namespace datasketches {
 
 template<typename W, typename A>