Count Reserved Words

#include <iostream.h>
#include <fstream.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

//Declare a key word structure

struct KeyWord
 {
	char keyword[20];
	int count;
 };

//Declare and initialize the table of keywords
KeyWord KeyWordTable[ ] =
{
	{"else", 0}, {"for", 0}, {"if", 0}, {"include", 0}, {"while, 0}
};

// a customized sequential search algorithm for keywords
int SeqSearch(KeyWord *tab, int n, char *word)
{
	int i;

	//scan list. compare word with keyword in current record
	for(i=0; i< n; i++, tab++)
		if(strcmp(word, tab->keyword)==0)
			return i;  //return index if match
	return -1; // sorry no match.
}

// Extract a word beginning with a letter and possibly other letters/digits.

int GetWord (ifstream& fin, char w[ ])
{
	char c;
	int i=0;

	//skip non-alphabetic input
	while(fin.get(c) && !isalpha(c))
		;

	//return 0 (Failure) on end of file
	if (fin.eof())
		return 0;

	//record 1st letter of the word.
	w[i++]=c;

	//collect letters and digits and NULL terminate string.
	while(fin.get(c) && (isalpha(c) || isdigit(c)))
		w[i++]=c;
	w[i]="\0";
	
	return 1;  //return 1 (Success)
}

void main(void)
{
	const int MAXWORD=50;  //max size of any word.

	//declare the table size and initialize its value.
	const int NKEYWORDS = sizeof(KeyWordTable)/sizeof(KeyWord);

	int n;
	char word[MAXWORD], c;
	ifstream fin;

	//open file with error checking
	fin.open("prg2_5.cpp", ios::in|ios::nocreate);
	if(!fin)
	{
		cerr<< "Could not open file 'prg2_5.cpp'" << endl;
		exit(1);
	}

	//extract words until end of file.
	while (GetWord(fin, word))
		//if a match in keyword table, increment count
		if ((n=SeqSearch(KeyWordTable,NKEYWORDS, word))!=-1)
			KeyWordTable[n].count++;

	//scan the keyword table and print record fields.
	for(n=0; n< NKEYWORDS; n++)
		if (KeyWordTable[n].count>0)
		{
			cout << KeyWordTable[n].count;
			cout << " " << KeyWordTable[n].keyword<<endl;
		}
	fin.close();
}
<Run of Program>

 else
 for
 if
 include
 while