Question

int bintodec(string); // converts a binary number (represented as a STRING) to decimal
int hextodec(string); // converts a hexadecimal number (represented as a STRING) to decimal
string dectobin(int); // converts a decimal number to binary (represted as a STRING)
string dectohex(int); // converts a decimal number to hexadecimal (represted as a STRING)

//the addbin and addhex functions work on UNsigned numbers

string addbin(string, string); // adds two binary numbers together (represented as STRINGS)
string addhex(string, string); // adds two hexadecimal numbers together (represented as STRINGS)

int main()
{
   cout<<"SIGNED binary 10011 = SIGNED decimal "<<bintodec("10011")<<endl;
   cout<<"SIGNED binary 01110 = SIGNED decimal "<<bintodec("01110")<<endl<<endl;
  
   cout<<"SIGNED hexadecimal A1 = SIGNED decimal "<<hextodec("A1")<<endl;
   cout<<"SIGNED hexadecimal 3C = SIGNED decimal "<<hextodec("3C")<<endl<<endl;
  
   cout<<"SIGNED decimal 25 = SIGNED binary "<<dectobin(25)<<endl;
   cout<<"SIGNED decimal -18 = SIGNED binary "<<dectobin(-18)<<endl<<endl;
  
   cout<<"SIGNED decimal 28 = SIGNED hexadecimal "<<dectohex(28)<<endl;
   cout<<"SIGNED decimal -15 = SIGNED hexadecimal "<<dectohex(-15)<<endl<<endl;
  
   cout<<"binary 1101 + 1000 = "<<addbin("1101", "1000")<<endl;
   cout<<"binary 11000 + 1011 = "<<addbin("11000", "1011")<<endl<<endl;
  
   cout<<"hexadecimal A4 + A5 = "<<addhex("A4", "A5")<<endl;
   cout<<"hexadecimal 2B + C = "<<addhex("2B", "C")<<endl<<endl;
      
   return 0;
  
}

int bintodec(string bin)
{

/*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
}

int hextodec(string hex)
{

/*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
  
}

string dectobin (int dec)
{
  
/*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
  
  
}

string dectohex(int dec)
{
  
/*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
  
}

string addbin(string bin1, string bin2)
{
  
   /*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
  
}

string addhex(string hex1, string hex2)
{
  
   /*
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
##### IMPLEMENT THIS #####
*/
  
  
  
}

Answer 1

int bintodec(string bin)
{

            int decimal, base, remainder;

            decimal = 0;

            base = 1;           

            int x = atoi(bin.c_str());             //String to integer conversion

            while (x > 0)

                        {

                       remainder = x % 10;

                                    decimal = decimal + remainder * base;

                       base = base * 2;

                       x = x / 10;

           }

            return x;        

}

int hextodec(string hex)

       {

              char arr[100];

              int len, i, test, length, decimal, base = 16;

              i = 0;

              strcpy(arr, hex.c_str());         //string to character array

              len = strlen(hex);

              len = len - 1;

              length = len;

              while (len > 0)

              {

                     test = arr[i];

                     if (test >= 48 && test <= 57)   // test Between 0-9

                     {

                           decimal += (test - 48) * pow(base, length - i - 1);

                     }

                     else if ((test >= 65 && test <= 70))   // test Between A-F

                     {

                           decimal += (test - 55) * pow(base, length - i - 1);

                     }

                     else if (test >= 97 && test <= 102)   // test Between a-f

                     {

                           decimal += (test - 87) * pow(base, length - i - 1);

                     }

                     else

                     { cout << "Not Hex value"; }

                     len = len -1;

                     i++ ;

              }

              return decimal;

       }

string dectobin(int dec)

{

       int remainder;

       if (dec <= 1)

       {

              cout << dec;

              return;

       }

       remainder = dec % 2;

       dectobin(dec / 2);

       cout << remainder;

}

string dectohex(int dec)          //use _itoa(), if itoa() does not work;

{                                       

       char buffer[50];

       itoa(dec, buffer, 16);

       cout << buffer;

}

string addbin(string bin1, string bin2)

{

       int num1, num2, result;

       num1 = bintodec(bin1);

       num2 = bintodec(bin2);

       result = num1 + num2;

       dectobin(result);

}

string addhex(string hex1, string hex2)

{

       int num1, num2, result;

       num1 = hextodec(hex1);

       num2 = hextodec(hex2);

       result = num1 + num2;

       dectohex(result);

}