object RemoveBitsShift {
/*
removeBitsAndShift(number, positions)
-------------------------------------
Removes multiple bit positions from a number and shifts the remaining bits
right to fill the gaps.
Important:
Bits must be removed from highest → lowest position.
Otherwise earlier removals shift the positions of later ones.
*/
def removeBitsAndShift(number: Int, positions: List[Int]): Int = {
// Sort positions descending
val sorted: List[Int] = positions.sortWith(_ > _)
var result: Int = number
for (pos: Int <- sorted) {
val left: Int = result >> (pos + 1) // bits above removed bit
val right: Int = result & ((1 << pos) - 1) // bits below removed bit
result = (left << pos) | right // merge
}
result
}
/*
printBinary(n)
--------------
Prints a 32-bit binary representation of an integer.
*/
def printBinary(n: Int): Unit = {
val binary: String = n.toBinaryString.reverse.padTo(32, '0').reverse
val grouped: String = binary.grouped(4).mkString(" ")
println(grouped)
}
def main(args: Array[String]): Unit = {
val number: Int = 1234 // 0000 0000 0000 0000 0000 0100 1101 0010
val positions: List[Int] = List(1, 3, 7) // remove bits 1, 3, 7 (0 = LSB)
println("Original number in binary:")
printBinary(number)
val result: Int = removeBitsAndShift(number, positions)
println("\nNumber after removing bits {1, 3, 7} and shifting remaining bits:")
printBinary(result)
println("\nResult as integer: " + result)
}
}
/*
run:
Original number in binary:
0000 0000 0000 0000 0000 0100 1101 0010
Number after removing bits {1, 3, 7} and shifting remaining bits:
0000 0000 0000 0000 0000 0000 1001 0100
Result as integer: 148
*/
