text: unset the bit at currentIndex
code: noOfWays += waysToKAdjacentSetBits ( n , k , currentIndex + 1 , adjacentSetBits , 0 ) ; } else if ( ! lastBit ) { noOfWays += waysToKAdjacentSetBits ( n , k , currentIndex + 1 , adjacentSetBits , 1 ) ; noOfWays += waysToKAdjacentSetBits ( n , k , currentIndex + 1 , adjacentSetBits , 0 ) ; } return noOfWays ; }