even-odd.l

%{
/*
1.Request input of an even and an odd number 
2.indicate input characteristic : Even/Odd [digit_length]
3.check for input's correctness and print result
*/

#include<stdlib.h>
#include<stdio.h>

int number_1;
int number_2;
%}


number_sequence [0-9]*

%%

{number_sequence}[0|2|4|6|8]		{
						printf("Even number [%d]",yyleng);
						return atoi(yytext);
					}

{number_sequence}[1|3|5|7|9]		{
						printf("Odd number [%d]",yyleng);	
						return atoi(yytext);
					}
%%

int yywrap
{
 	return 1;
}
 
int main()
{
	printf("\nInput an even number and an odd number\n");
 	number_1 = yylex();
	number_2 = yylex();
	int diff = number_1 - number_2;
	if(diff%2!=0)
		printf("\nYour inputs were checked for correctness, \nResult : Correct\n");
	else
		printf("\nYour inputs were checked for correctness, \nResult : You do not know how to read\n");
	return 1;
}