some more solves

contests/6contest/3.cpp

@@ -0,0 +1,26 @@
+#include <iostream>
+#include <vector>
+#include <functional>
+
+
+template <typename It, typename F>
+void myapply(It first, It last, F f) {
+    for (It it = first; it != last; ++it) {
+        f(*it);
+    }
+
+    return;
+}
+
+template <typename It, typename Pred>
+std::vector<std::reference_wrapper<typename std::iterator_traits<It>::value_type>> myfilter2(It first, It last, Pred f) {
+    std::vector<std::reference_wrapper<typename std::iterator_traits<It>::value_type>> result;
+
+    for (It it = first; it != last; ++it) {
+        if (f(*it)) {
+            result.push_back(std::ref(*it));
+        }
+    }
+
+    return result;
+}