text: If this is not an illegal move then make this move .
code: if ( ( piles [ i ] ^ nim_sum ) < piles [ i ] ) { ( * moves ) . pile_index = i ; ( * moves ) . stones_removed = piles [ i ] - ( piles [ i ] ^ nim_sum ) ; piles [ i ] = ( piles [ i ] ^ nim_sum ) ; break ; } } }