lab for Gaidel' №4 var 4

// Лабораторная работа для Гайделя №4 вариант 4

#include<iostream>
#include<fstream>
#include<string>
#include<map>

using namespace std;


bool Prod()
{
    cout << "Continue Y/N" << endl;
    char yn;
    cin >> yn;
    cin.clear();
    if (yn == 'Y' && cin.get() == '\n') return true;
    else if (yn == 'N' && cin.get() == '\n') return false;
    else
    {
        while (cin.get() != '\n');
        cout << "Error. Try again" << endl;
        Prod();
    }
}

int main()
{
    setlocale(LC_ALL, ".1251");

    string fileName;

    do {
        ifstream file;
        do {
            cout << "Input a filename > ";
            cin >> fileName;
            file.open(fileName);
            if (file.good())
                break;
            cout << "Error: File not found" << endl;
        } while (true);

        map <char, int> chars;
        map <char, int>::iterator begin, at, end;

        string str;
        if (file.is_open())
        {
            while (file)
            {
                getline(file, str);
                for (int i = 0; i < str.length(); i++) {
                    chars[str[i]]++;// считаем каждый символ
                }
                str = "";
            };
            file.close();

            begin = chars.begin();
            end = chars.end();

            for (at = begin; at != end; at++)
            {
                int i = 0;
                double coef = (double)at->second / chars.size();
                cout << at->first << " >" << at->second << " times >" << coef << endl; // выводим результат
                i++;
            }
        }
    } while (Prod());

    system("pause");
    return 0;
}