In a window , if A [ i ] is a even number with even times fliped , it need to be fliped again . On other hand , if A [ i ] is a odd number with odd times fliped , it need to be fliped again .
if ( A [ i ] % 2 == len ( flip ) % 2 ) : NEW_LINE INDENT if ( i + K - 1 >= N ) : NEW_LINE INDENT return - 1 NEW_LINE DEDENT DEDENT