#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>                // for exit
#include "apstring.h"
#include "apvector.h"
#include "systimer.h"              // for SysTimer
#include "prompt.h"
#include "strutils.h"              // for StripPunc and ToLower

// author: Owen Astrachan
//
// lists all words in an input file, with word counts
//
// 5/28/97

const int NOT_FOUND = -1;

struct WordStat
{
    apstring info;               // the apstring
    int count;                   // # of times apstring occurs
};


int Search(const apvector<WordStat> & list, int numWords,
	   const apstring & key)
// precondition: numWords = # entries in list    
// postcondition: returns index at which key occurs in list
//                returns NOT_FOUND if key does not occur
{
    int k;
    for(k=0; k < numWords; k++)
    {
	if (list[k].info == key)
	{
	    return k;
	}
    }
    return NOT_FOUND;
}

void Update(apvector<WordStat> & list, int & numWords,
	    const apstring & word)
// precondition: numWords = # entries in list
// postcondition: number of occurrences of word in list is updated
//                i.e., incremented by 1 or word is added to list
{
    int location = Search(list,numWords,word);

    if (location != NOT_FOUND)
    {
	list[location].count++;
    }
    else
    {
	if (numWords >= list.length())         // grow if needed
	{
	    list.resize(list.length() * 2);
	}
	list[numWords].info = word;
	list[numWords].count = 1;
	numWords++;
    }
}

void Print(const apvector<WordStat> & list, int numWords)
// precondition: numWords = # entries in list    
// postcondition: all elements of list printed
{
    int k;
    for(k=0; k < numWords; k++)
    {
        cout << list[k].count << "\t" << list[k].info << endl;
    }
    cout << endl << "# of words = " << numWords << endl;
}


int main()
{
    apstring filename = PromptString("enter name of file: ");
    apstring word;                       // word read from file
    ifstream input;
    apvector<WordStat> list(1000);
    int numWords = 0;
    
    SysTimer timer;

    
    input.open(filename.c_str());
    if (input.fail())
    {
        cout << "could not open file " << filename << endl;
        exit(0);
    }
    
    while (input >> word)              // reading word succeeded
    {
	ToLower(word);
	StripPunc(word);
        timer.start();
        Update(list,numWords,word);
        timer.stop();
    }

    Print(list,numWords);
    cout << "total time for update = " << timer.cumulativeTime() << endl;    
}