??? sprint 5

#include <iostream>
#include <vector>
#include <iterator>
using namespace std;

template <typename RandomIt>
pair<RandomIt, RandomIt> FindStartsWith(RandomIt range_begin, RandomIt range_end, char prefix) {
    if (range_begin == range_end)
        return { range_begin, range_end };
    if ((*range_begin)[0] > prefix)
        return{ range_begin,range_begin };
    pair<RandomIt, RandomIt> result;

    auto it = range_begin;
    bool flag = false;
    do {
        if ((*it)[0] == prefix) {
            result.first = it;
            flag = true;
        }
        advance(it, 1);
    } while ((*prev(it))[0] != prefix && it != range_end&& (*it)[0]<=prefix);
    if (flag == false)
        return { it,it };
    flag = false;
    while (it != range_end) {
        advance(it, 1);
        if ((*prev(it))[0] == prefix) {
            result.second = it;
            flag = true;
        }
        if (flag == true)
            return result;
    }
    result.second = next(result.first);
    return result;
}

int main() {
        const vector<string> sorted_strings = { "moscow", "murmansk", "vologda" };
        const auto m_result = FindStartsWith(begin(sorted_strings), end(sorted_strings), 'm');
        for (auto it = m_result.first; it != m_result.second; ++it) {
            cout << *it << " ";
        }
        cout << endl;
        const auto p_result = FindStartsWith(begin(sorted_strings), end(sorted_strings), 'm');
        cout << (p_result.first - begin(sorted_strings)) << " " << (p_result.second - begin(sorted_strings)) << endl;
        const auto z_result = FindStartsWith(begin(sorted_strings), end(sorted_strings), 'v');
        cout << (z_result.first - begin(sorted_strings)) << " " << (z_result.second - begin(sorted_strings)) << endl;

        const vector<string> words = {"bara"};
        auto range_begin = words.begin();
        auto range_end = words.end();
        const auto q_result = FindStartsWith(begin(words), end(words), 'a');
        cout << (q_result.first - begin(words)) << " " << (q_result.second - begin(words)) << endl;
        const auto w_result = FindStartsWith(range_begin, range_end, 'b');
        cout << (w_result.first - begin(words)) << " " << (w_result.second - begin(words)) << endl;
        const auto e_result = FindStartsWith(range_begin, range_end, 'c');
        cout << (e_result.first - begin(words)) << " " << (e_result.second - begin(words)) << endl;
        const auto s_result = FindStartsWith(begin(words), end(words), 'z');
        cout << (s_result.first - begin(words)) << " " << (s_result.second - begin(words)) << endl;
        return 0;
}