#include<stdio.h>
#include<string.h>
#include<conio.h>
#include<ctype.h>

int decode[1000],decodeLen=0;
int hexToDec(char c)
{
    c=toupper(c);
    if(c>='A' && c<='F')
       return c-'A'+10;
    else if(c>='0' && c<='9')
       return c-48;
}
void asciiDecode(char str[])
{
     FILE *fpWrite;
     fpWrite=fopen("c:\\score2.txt","at");
     int i,l,x,y,num;
     l=strlen(str);
     for(i=0;i<l;i=i+2)
     {
                      x = hexToDec(str[i]);
                      y = hexToDec(str[i+1]);
                      num=(x*16)+(y*1);
                      if(num>=1 && num <= 127)
                      {
                          printf("%c",num);
                          decode[decodeLen]=num;
                          decodeLen++;
                          fprintf(fpWrite,"%c",num);

                      }
     }
     fclose(fpWrite);
}

void reverseCode()
{
     FILE *fpWrite;
     fpWrite=fopen("c:\\score2.txt","at");
     int i,j,count;
     count=decodeLen;
     for(i=0;i<decodeLen;i++)
     {
                    if( (i+1)%4==0)
                     {
                         for(j=i;j>=i-3;j--)
                         {
                                            printf("%c",decode[j]);
                                            fprintf(fpWrite,"%c",decode[j]);
                         }
                         count=i;
                     }
                     if(i==decodeLen-1  && i-count < 4)
                     {
                                for(j=i;j>=count+1;j--)
                                {
                                                       printf("%c",decode[j]);
                                                       fprintf(fpWrite,"%c",decode[j]);
                                }
                    }
     }
     fclose(fpWrite);

}
int main()
{
    FILE *fp;
    char str[1000];
    fp = fopen("c://score1.txt","r");
    while(fscanf(fp,"%s",str)!=EOF)
    {

                                                asciiDecode(str);

    }
    printf("\n\nAfter Reverse: ");
    reverseCode();
    fclose(fp);
    scanf(" ");
    return 0;
}