Returns true if a string str [ st . . end ] is palindrome
def isPalin ( str , st , end ) : NEW_LINE INDENT while ( st < end ) : NEW_LINE INDENT if ( str [ st ] != str [ end ] ) : NEW_LINE INDENT return False NEW_LINE DEDENT st += 1 NEW_LINE end - - 1 NEW_LINE DEDENT return True NEW_LINE DEDENT