object BitCheck {
def printBits(value: Long, width: Int): Unit = {
for (i <- (0 until width).reverse) {
val mask = 1L << i
print(if ((value & mask) != 0) "1" else "0")
}
}
def exactBitSet(pos1: Int, pos2: Int, value: Long): Boolean = {
if (pos1 < 0 || pos2 < 0 || pos1 >= 64 || pos2 >= 64) return false
if (pos1 == pos2) return false
val mask = (1L << pos1) | (1L << pos2)
value == mask
}
def main(args: Array[String]): Unit = {
val tests = Seq(
(0b1000010000L, 4, 9, 10),
(0b0010000010L, 1, 7, 10),
(0b0000100100L, 2, 5, 10),
(0b1000010000L, 3, 9, 10),
(0b1001010000L, 4, 9, 10),
(0b1111111111L, 4, 9, 10),
(0b0000000000L, 4, 9, 10),
(0b1000010000L, 4, 8, 10),
(1L, 0, 0, 1),
(1L, 0, 1, 1),
(0L, 1, 1, 1)
)
for ((value, x, y, width) <- tests) {
printBits(value, width)
print(s" bits($x, $y) -> ")
println(exactBitSet(x, y, value))
}
}
}
/*
OUTPUT:
1000010000 bits(4, 9) -> true
0010000010 bits(1, 7) -> true
0000100100 bits(2, 5) -> true
1000010000 bits(3, 9) -> false
1001010000 bits(4, 9) -> false
1111111111 bits(4, 9) -> false
0000000000 bits(4, 9) -> false
1000010000 bits(4, 8) -> false
1 bits(0, 0) -> false
1 bits(0, 1) -> false
0 bits(1, 1) -> false
*/
