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320
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1 |
object CW6a {
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167
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2 |
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320
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3 |
//(1) Complete the collatz function below. It should
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// recursively calculate the number of steps needed
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// until the collatz series reaches the number 1.
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// If needed, you can use an auxiliary function that
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// performs the recursion. The function should expect
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// arguments in the range of 1 to 1 Million.
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323
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def stepsCounter(n: Long, s: Long) : Long = n match{
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case 1 => s
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case n if(n%2==0) => stepsCounter(n/2,s+1)
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case _ => stepsCounter(3*n+1, s+1)
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}
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def collatz(n: Long) : Long = n match {
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case n if(n>0) => stepsCounter(n,0)
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case n if(n<=0) => stepsCounter(1,0)
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}
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281
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19 |
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126
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20 |
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320
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21 |
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//(2) Complete the collatz_max function below. It should
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// calculate how many steps are needed for each number
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// from 1 up to a bound and then calculate the maximum number of
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// steps and the corresponding number that needs that many
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// steps. Again, you should expect bounds in the range of 1
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// up to 1 Million. The first component of the pair is
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// the maximum number of steps and the second is the
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// corresponding number.
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323
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def collatz_max(bnd: Long) : (Long, Long) = {
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val allCollatz = for(i<-1L until bnd) yield collatz(i)
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val pair = (allCollatz.max, (allCollatz.indexOf(allCollatz.max) +1).toLong)
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pair
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126
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}
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36 |
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127
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}
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