#include<stdio.h>
#include<ctype.h>
#include<string.h>
#include<malloc.h>
#include<iostream.h>
#include<stdlib.h>
struct list {
   struct list   *next ;
   char          *name ;
   int           counter;
};

#define MAXWORD  100
#define HASHSIZE 101

typedef struct list list;
list *hashtable[HASHSIZE];


// hashfunction of the hashtable
unsigned  hashfunc(char *s);
list *lookup(char  *s,list *hasht[]);
list *insert(char  *s,list *hasht[]);
//duplicate of s
char *strdup(char *s);
// this function  finds  the next  word
int findword(FILE *fp, char *word, int lim);

int findword(FILE *fp ,char *word, int lim)
{
   int c ;

   char *w = word;

   while(isspace(c = getc(fp)))
	 ;
   if (c != EOF)
      *w++ =c;
   if(!isalpha(c)) {
	*w = '\0';
	return c;
   }

   for( ; --lim > 0 ; w++)
      if(!isalnum(*w = getc(fp)))
      {
	  ungetc(*w, fp);
	  break;
      }
  *w ='\0';
  return word[0];
}





char *strdup(char *s)
{
   char *p;
   p=(char *) malloc(strlen(s)+1);
   if(p!=NULL)
      strcpy(p,s);
   return p;
}





unsigned  hashfunc(char *s)
{
   unsigned hashval;

   for(hashval = 0; *s!='\0' ; s++)
	hashval = *s + 31*hashval;
   return (hashval % HASHSIZE);
}

list *lookup(char  *s,list *hasht[])
{
   list *np;

   for (np= hasht[hashfunc(s)]; np!=NULL; np=np->next)
      if(strcmp(s,np->name) == 0)
	   return np;  //found
   return NULL;  // not found
}
list *insert(char *name,list *hasht[])
{
   list *np;
   unsigned hashval;

   if((np = lookup(name,hasht)) == NULL)   { //not found
     np = (list *) malloc(sizeof(*np));
     if(np==NULL || (np->name = strdup(name)) == NULL)
		 return NULL;
     hashval = hashfunc(name);
     np->next =  hasht[hashval];
     hasht[hashval] = np;
     np->counter=1;
   }
   else
       np->counter++;

   return np;
}


main(int argc ,char *argv[])
{
  FILE *fp;
  char word[MAXWORD];
  list *plist,*np;
//  list *hasht[HASHSIZE];
  if (argc!=2) {
    printf("Error in using the program !");
    printf("\n Usage : C:\ progname filename ");
    }
  if((fp=fopen(argv[1],"r"))==NULL)  {
      printf("cannot open file\n");
      exit(1);
   }

 // hashtable=( list* ) NULL;
  while(findword(fp,word,MAXWORD) != EOF)
     if(isalpha(word[0]))
	plist= insert(word,hashtable) ;

  for(int i=0; i<101 ; i++)
     for (np= hashtable[i]; np!=NULL; np=np->next)
      {
       if(np!=NULL)
       {
       cout<<"The word :  " << np->name<<" appeared  " ;
       cout << np->counter<<" times. \n";
       }
      }

}