Lex specification program that generates a C program which takes a string “abcd" and generates pattern

Lex specification program that generates a C program which takes a string “abcd" and generates pattern

/*Write a Lex specification program that generates a C program which takes a string

“abcd” and prints the following output.

        abcd

        abc

        ab

        a

*/

%{ 

#include<stdio.h>

char i,j;

%}

%%

[a-z]* { for(i='d';i>=1;--i)

      {

           for(j='a';j<=i;++j)

           {

              printf("%c ",j);

           }

          printf("\n");

      }

}

%%

int main()

{

 yylex();

 return 0;

}

//output of this code