#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>                // for exit
#include "CPstring.h"
#include "vector.h"
#include "ctimer.h"                // for CTimer
#include "strutils.h"              // for StripPunc

// author: Owen Astrachan
//
// lists all words in an input file, with word counts
// uses class WordList to encapsulate behavior
//
// 5-15-95


struct WordStat
{
    string info;                 // the string
    int count;                   // # of times string occurs
    WordStat * next;             // pointer to next node in list
};


class WordList
{
  public:
    WordList();                     // constructor
    ~WordList();                    // destructor
    void Update(const string & word);  // update occurrences of word
    int GetUnique();                // return # of unique words in list
    int GetTotal();                 // return # of total words in list
    void Print(ostream & output);   // print all words in list
  private:

    int myCount;                    // # of entries stored in myList
    int myTotal;                    // # of words (non-unique)
    WordStat * myList;              // pointer to first node of list
    
    WordStat * Search(const string & key); // returns pointer
};

WordList::WordList()
   : myCount(0),
     myTotal(0),
     myList(0)
{
    // all work done in initializer list
}

WordList::~WordList()
// postcondition: all new'd storage deleted     
{
    WordStat * current = myList;
    while (current != 0)
    {
	myList = myList->next;       // advance to next
	delete current;              // delete current (first)
	current = myList;            // reset current
    }
}

WordStat * WordList::Search(const string & key)
// postcondition: returns pointer to struct with key
//                returns 0 if key does not occur
// performance: O(n), n = # items in myList                    
{
    WordStat * current = myList;
    while (current != 0)
    {
	if (current->info == key)
	{
	    return current;
	}
	current = current->next;
    }
    return 0;
}

void WordList::Update(const string & word)
// postcondition: updates occurrence of word
//                adds word to list if not already present
//                otherwise updates count of # occurrences     
//                increments count of total # of words     
{
    WordStat * loc = Search(word);
    myTotal++;

    if (loc != 0)
    {
	loc->count++;
    }
    else
    {
	myCount++;
	WordStat * wptr = new WordStat; // create new node
	wptr->info  = word;             // store values
	wptr->count = 1;                // initialize all fields
	wptr->next  = 0;
	
	
	if (myList == 0)                // any nodes at all?
	{
	    myList = wptr;
	}
	else if (word < myList->info)   // goes in front?
	{
	    wptr->next = myList;
	    myList = wptr;
	}
	else
	{
	    loc = myList;
	    while (loc->next && loc->next->info < word)
	    {
		loc = loc->next;
	    }
	    wptr->next = loc->next;
	    loc->next = wptr;
	}
    }
}

void WordList::Print(ostream & output)
// postcondition: all elements of list printed, sorted alphabetically     
{
    WordStat * current = myList;
    while (current != 0)
    {
	output << current->count << "\t" << current->info << endl;
	current = current->next;
    }
    output << endl << "# of words = " << myCount << endl;    
}


int WordList::GetUnique()
// postcondition: returns # unique words in list     
{
    return myCount;
}

int WordList::GetTotal()
// postcondition: returns total # of words in list
//                same as # of times Update called     
{
    return myTotal;
}

int main()
{
    string word;                       // word read from file
    string filename;                   // name of file
    ifstream input;
    WordList wlist;
    CTimer timer;
    double processTime;
    
    cout << "enter name of file: ";
    cin >> filename;
    
    input.open(filename);
    if (input.fail())
    {
        cout << "could not open file " << filename << endl;
        exit(0);
    }
    
    while (input >> word)              // reading word succeeded
    {
        word = word.Downcase();
        StripPunc(word);
        timer.Start();
        wlist.Update(word);
        timer.Stop();
    }

    processTime = timer.CumulativeTime();
    wlist.Print(cout);

    cout << "total words (non-unique): " << wlist.GetTotal() << endl;
    cout << "total time for update = " << processTime << endl;
    return 0;
}