Напечатать гистограммы длин вводимых слов - C (СИ)

#include <stdio.h>
 
#define NULL 0
#define YES 1
 
main () {
    int c, lword, endword;
    lword = endword = NULL;
    while ( ( c = getchar ( ) ) != EOF ) {
        if ( c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' )
            ++lword;
        else
            endword = YES;
        if ( endword && lword ) {
            for (int i = NULL; i < lword; i++ )
                printf ( "*" );
            printf ( "\n" );
            endword = lword = NULL;
        }
    }    
}