#include <iostream>
#include "converters.h"
#include <cctype>

using namespace std;

char IntToDecimalDigit(int value) {
    char  digit{'x'};

    if (value >= 0 and value <= 9) {
        digit = static_cast<char>(value + '0');
    } else {
        cout << "Error: in IntToDecimalDigit"
             << value  << " is not a valid decimal digit " << endl;
    }

    return digit;
}


int DecimalDigitToInt(char digit) {
     int returnValue{0};

     if (isdigit(digit)) {
          returnValue = digit -'0';
     }else {
        cout << "Error: in DecimalDigitToInt "
             << digit  << " is not a valid decimal digit " << endl;
     }

     return returnValue;
}


string IntegerToString(int value) {
    string number;
    int digit;
   
    if (value == 0) {
       number = "0";
    } else {
        while (value > 0) {
            digit = value % 10;
            value = value / 10;
            number = IntToDecimalDigit(digit) + number;
        }
    }

    return number;
}

int StringToInteger(string num){
     int value{0};
     size_t i;

     for(i = 0; i < num.size() ; ++i) {
         value = value * 10 +  DecimalDigitToInt(num[i]);
     }

     return value;
}