seminar04 06_pairing

seminar04_templates/06_pairing/main.cpp

@@ -0,0 +1,65 @@
+#include <iostream>
+#include <vector>
+#include <array>
+#include <string>
+#include <utility>
+using std::cout, std::endl, std::vector, std::pair;
+
+template <typename T, typename U>
+std::ostream& operator<<(std::ostream& out, const std::pair<T, U>& p)
+{
+    out << "(" << p.first << ", " << p.second << ")";
+    return out;
+}
+
+template <typename T>
+std::ostream& operator<<(std::ostream& out, const std::vector<T>& v)
+{
+    out << "[";
+    for (size_t i = 0; i < v.size() - 1; ++i)
+        out << v[i] << ", ";
+
+    if (!v.empty())
+    {
+        out << v.back();
+    }
+    out << "]";
+    return out;
+}
+
+template <typename T>
+vector<pair<typename T::value_type,typename T::value_type>> pairing(T& xs) {
+    typedef typename T::value_type U;
+    vector<pair<U, U>> res;    
+
+    size_t size = xs.size();
+
+    for (int i = 0, n = (size % 2 ? size - 1: size); i < n; i += 2)
+        res.push_back(pair(xs[i], xs[i+1])); 
+    if (size % 2)
+            res.push_back(pair(xs[size - 1], U()));
+    return res;
+}
+
+int main()
+{
+    std::vector v {10, 20, 30, 40, 50, 60};
+    cout << pairing(v) << endl;
+
+
+    std::array<std::string, 7> a {"cat", "dog", "mouse", "elephant", "tiget", "axolotl", "wolf"};
+    cout << pairing(a) << endl;
+
+
+    std::string s {"Cats and dogs!"};
+    cout << pairing(s) << endl;
+}
+
+
+/*
+    Программа должна напечатать:
+
+    [(10, 20), (30, 40), (50, 60)]
+    [(cat, dog), (mouse, elephant), (tiget, axolotl), (wolf, )]
+    [(C, a), (t, s), ( , a), (n, d), ( , d), (o, g), (s, !)]
+*/