init commit

contests/6contest/1.cpp

@@ -0,0 +1,21 @@
+#include <iterator>
+
+template <typename Container>
+typename Container::value_type process(const Container& container) {
+    using ValueType = typename Container::value_type;
+
+    if (container.empty()) {
+        return ValueType{};
+    }
+
+    auto it = container.rbegin();
+    ValueType sum = *it;
+
+    for (int i = 0; it != container.rend() && i < 5; ++i, ++it) {
+        if (i == 2 || i == 4) {
+            sum += *it;
+        }
+    }
+
+    return sum;
+}

contests/6contest/2.cpp

@@ -0,0 +1,16 @@
+// #include <iostream>
+// #include <vector>
+#include <iterator>
+
+template <typename Container, typename Predicate>
+Container myfilter(const Container& container, Predicate pred) {
+    Container result;
+
+    for (const auto& x : container) {
+        if (pred(x)) {
+            result.insert(result.end(), x);
+        }
+    }
+
+    return result;
+}

contests/6contest/5.cpp

@@ -0,0 +1,19 @@
+#include <iterator>
+#include <functional>
+
+template <typename ForwardIt, typename Compare = std::less<>>
+void selection_sort(ForwardIt first, ForwardIt last, Compare comp = Compare()) {
+    for (auto fit = first; fit != last; ++fit) {
+        auto min_it = fit;
+
+        for (auto sit = std::next(fit); sit != last; ++sit) {
+            if (comp(*sit, *min_it)) {
+                min_it = sit;
+            }
+        }
+
+        std::swap(*fit, *min_it);
+    }
+
+    return;
+}