/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the  Free Software  Foundation, either  version 3 of the License, or
(at your option) any later version.

This  program  is  distributed  in the hope that  it  will be useful,
but  WITHOUT ANY  WARRANTY; without  even  the  implied  warranty  of
MERCHANTABILITY  or FITNESS  FOR  A  PARTICULAR  PURPOSE. See the GNU 
General Public License for more details.

You should  have received  a copy  of the  GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

 Author:         Marco Vitetta
 E-mail:         <vito3200@hotmail.it>
 WebSite:        http://ervito.altervista.org
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int count_letters(char *string);
char *itow(int value);              // itow() needs string.h library
char NUMBERS_IN_WORDS[][11]={       // and the initialization below.
      "zero ",
      "one ",
      "two ",
      "three ",
      "four ",
      "five ",
      "six ",
      "seven ",
      "eight ",
      "nine ",
      "ten ",
      "eleven ",
      "twelve ",
      "thirteen ",
      "fourteen ",
      "fifteen ",
      "sixteen ",
      "seventeen ",
      "eighteen ",
      "nineteen ",
      "twenty",
      "thirty",
      "forty",
      "fifty",
      "sixty",
      "seventy",
      "eighty",
      "ninety",};
int main()
{
      int sum=0,value;

      for(value=1;value<1001;value++)
            sum+=count_letters(itow(value));
      printf("\n\t%i\n\n",sum);
      return 0;
}
int count_letters(char *string)
{
      int index=0,length=strlen(string),letters=0;

      for(;index<length;index++)
            if( (string[index]>='a' && string[index]<='z')||
                (string[index]>='A' && string[index]<='Z') )
                  letters++;
      return letters;
}
char *itow(int value)                                                         // "Int TO Words" function
{
      char digits[13]="000000000000",*words;
      int digits_number,index;
      words=malloc(50*sizeof(char));

      if(value<0)
      {
            sprintf(words,"minus ");
            value=-value;
      }
      digits_number=sprintf(digits,"%i",value);
      if(digits_number%3!=0)                                                  // The string will be parsed in 3-digits tokens
      {
            do
            {
                  for(index=digits_number+3-(digits_number%3);index-->0;)
                        digits[index+1]=digits[index];
                  digits[0]='0';
            }while(digits[digits_number+3-(digits_number%3)]!='\0');
            digits_number+=3-(digits_number%3);
      }
      do
      {
            for(index=0;index<3;index++)              //----------------//----------//----------------//----------------------------------------
                  if(digits[index]-48!=0)             //   CONVERSION   //  Digits  //  0  1  2  ...  //  In the ASCII table the numeric digits
                  {                                   //                //    |     //  |  |  |   |   //  are shifted  of 48 respect their real
                        if(index==0)                  //     TABLE:     //  ASCII   // 48 49 50  ...  //  values!
                        {                             //----------------//----------//----------------//----------------------------------------
                              strcat(words,NUMBERS_IN_WORDS[digits[index]-48]);
                              strcat(words,"hundred");
                              if(digits[1]-48!=0 || digits[2]-48!=0)
                                    strcat(words," and");
                              else
                                    index=3;
                              strcat(words," ");
                        }
                        else
                        {
                              if(index!=1)
                                    strcat(words,NUMBERS_IN_WORDS[digits[index]-48]);
                              else
                              {
                                    if(digits[1]-48<2)
                                          strcat(words,NUMBERS_IN_WORDS[digits[++index]-38]);
                                    else
                                          strcat(words,NUMBERS_IN_WORDS[digits[1]-30]);
                              }
                        }
                  }
            if(digits_number>9)
                  strcat(words,"billion ");
            else
                  if(digits_number>6)
                        strcat(words,"million ");
                  else
                        if(digits_number>3)
                              strcat(words,"thousand ");
            for(index=0;index<digits_number;index++)
                  digits[index]=digits[index+3];
            digits_number-=3;
            digits[digits_number]='\0';
      }while(digits_number>0);
      return words;
}