range update using lazy prpagation
void RangeUpdate ( int us , int ue , int ns , int ne , int ind ) { if ( lazy [ ind ] != 0 ) { seg [ ind ] = UpdateUtil ( seg [ ind ] ) ; if ( ns != ne ) { lazy [ ind * 2 ] ^= lazy [ ind ] ; lazy [ ind * 2 + 1 ] ^= lazy [ ind ] ; } lazy [ ind ] = 0 ; }