How do it without using asci code ? any hint that you can provide?
Charecter Type?
When we are dealing with character related problems, ascii codes are the only way out.
So we remember that uppercase letters are from 65 to 90, and lower case from 97 to 122.
Or you can do subtractions like,
if(ch-‘a’>=0&&ch-‘a’<122) return lowercase