Function wordCardinalityForBitmapRange

util.go:200–211

(bitmap []uint64, start int, end int)

}

func wordCardinalityForBitmapRange(bitmap []uint64, start int, end int) uint64 {
	answer := uint64(0)
	if start >= end {
		return answer
	}
	firstword := start / 64
	endword := (end - 1) / 64
	for i := firstword; i <= endword; i++ {
		answer += popcount(bitmap[i])
	}
	return answer
}

func selectBitPosition(w uint64, j int) int {
	seen := 0