public class MyClass {
static boolean is_letter(char x) {
return ((x >= 'a' && x <= 'z') || (x >= 'A' && x <= 'Z'));
}
static void reverse(char s[]) {
int right = s.length - 1, left = 0;
while (left < right) {
if (!is_letter(s[left]))
left++;
else if (!is_letter(s[right]))
right--;
else {
char tmp = s[left];
s[left] = s[right];
s[right] = tmp;
left++;
right--;
}
}
}
public static void main(String args[]) {
String str = "a#b$%c&*(def!";
char[] s = str.toCharArray();
reverse(s);
System.out.println(s);
}
}
/*
run:
f#e$%d&*(cba!
*/