Use scala 3. Replace your solutions with the symbols "???". Do not use external libraries. Make sure your solution is correct.
/*
 * Assignment:  Single bit-error correction
 *
 * Motivation:
 * While individual computers are fairly reliable devices, hardware 
 * failures become a regular occurrence as the system size is scaled up 
 * from an individual computer to, say, a warehouse-scale compute cluster.
 * When designing such systems, careful attention needs to be paid to
 * __fault tolerance__. That is, the system must be engineered to 
 * automatically and transparently recover from small hardware failures. 
 * Individual bit errors in DRAM (dynamic random access memory) modules 
 * are among such failures, as you can discover from the following 
 * large-scale field study available at Google Research:
 * 
 * http://research.google.com/pubs/pub35162.html
 *
 * Description:
 * This assignment asks you to study the principles of error-correcting
 * codes, after which you get to design your own error-correction scheme
 * to protect data stored in a (hypothetical) DRAM module from bit-errors.
 * (We only give you the specification that your design needs to meet.)
 *
 * Hint: 
 * To successfully solve this assignment, you may want to study, for 
 * example, the Hamming codes.
 *
 * http://en.wikipedia.org/wiki/Hamming_code
 *
 */

package object errorCorrect:

  /*
   * Task: Single bit-error correction
   *
   * Suppose you have available a memory module whose storage elements are 
   * 40-bit words. Each storage element is subject to bit errors, that is,
   * each bit in the 40-bit word may change its state from 0 to 1 or vice 
   * versa in a manner that we as system designers cannot control. 
   *
   * Using the 40-bit storage elements, we want implement a storage
   * scheme for 32-bit data words that is able to always recover the 
   * original data word if __at most one bit error__ has occurred during 
   * storage. That is, any individual bit in the storage element may 
   * experience a bit error, and we must still be able to recover the 
   * original data word from the bits stored in the storage element.
   * In particular, this requires that we __encode__ the 32-bit word
   * into a 40-bit word that gets saved into the storage element,
   * and __decode__ the 40-bit word loaded from the storage element 
   * back into the 32-bit word. Decoding must always succeed if at most
   * one bit error has occurred during storage. (The result of decoding
   * may be arbitrary if there has been more than one bit error.) 
   *
   * This task asks you to design encoding and decoding functions
   * that implement the previous specification.
   *
   */

  /** Returns, in the least significant 40 bits of the return value,
   *  the 40-bit encoded form of the 32-bit data word given as parameter. */

  def SECEncode(d: Int): Long = 
    ???
  end SECEncode

  /** Returns the 32-bit data word encoded in the least significant 40 bits
   *  of the parameter s. Decoding must always succeed if at most one
   *  bit error has occurred in the least significant 40 bits of the 
   *  parameter s. */

  def SECDecode(s: Long): Int = 
    ???
  end SECDecode

Make sure your code fulfils this test:
package errorCorrect

import org.scalatest.flatspec.AnyFlatSpec
import org.scalatest.matchers.should._
import scala.util.Random

class errorCorrectSpec extends AnyFlatSpec with Matchers:
    "the SEC encoding and decoding algorithm" should "return the correct value" in {
        val repeats = 100
        val seed    = 0x1234567890ABCDEFL
        val rnd     = new Random(seed)
        for j <- 1 to repeats do
            val d = rnd.nextInt()
            val s = SECEncode(d)
            val k = rnd.nextInt(64)
            val e = (s ^ (1L << k)) & 0x000000FFFFFFFFFFL
            withClue("For d = 0x%08X, s = 0x%010X, k = %2d, e = 0x%010X\n".format(d,s,k,e)) {
                SECDecode(e) shouldBe d
            }
    }