qn1b.l

%{
	int in_string_array(char*, char**, int);
	char **words;
	int words_count = 0;
%}

%%

	/* Match all words */
[^ \t\n]+ 	{
				//Check if word already exists
				if(!in_string_array(yytext, words, words_count)){
					words = (char**)realloc(words, (words_count+1)*sizeof(*words)); //Expanding array size dynamically
					//sizeof(char*) is 8 bits for 64-bit, 4 bits for 32-bit
					//allocate memory in word list for new word
					words[words_count] = (char*)malloc(sizeof(yytext));
					//copy new word into word list
					strcpy(words[words_count], yytext);
					words_count++;
				}
			}
	/* Match nothing else */
. 	;
\n 	;

%%

int in_string_array(char *word, char **words, int words_length){
	// Checks if the specified string is in the string array
	int i;
	for(i = 0; i < words_length; i++){
		if(strcmp(word, words[i]) == 0){
			return 1;
		}
	}
	// No match found
	return 0;
}

int main(int argc, char *argv[]){
	yyin = fopen(argv[1], "r");
	yylex();
	int total_words = words_count;
	int i;
	for(i = 0; i < total_words; i++){
		printf("%d - %s\n", i + 1, words[i]);
	}
	printf("\n\nTotal unique words: %d\n\n", total_words);
	fclose(yyin);
	return 0;
}