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Christian Urban <christian.urban@kcl.ac.uk> 
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     1  | 
// Core Part 1 about the 3n+1 conjecture
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Christian Urban <christian.urban@kcl.ac.uk> 
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     2  | 
//============================================
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Christian Urban <christian.urban@kcl.ac.uk> 
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     3  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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     4  | 
object C1 {
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Christian Urban <christian.urban@kcl.ac.uk> 
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     5  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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//(1) Complete the collatz function below. It should
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Christian Urban <christian.urban@kcl.ac.uk> 
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     7  | 
//    recursively calculate the number of steps needed 
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Christian Urban <christian.urban@kcl.ac.uk> 
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//    until the collatz series reaches the number 1.
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Christian Urban <christian.urban@kcl.ac.uk> 
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     9  | 
//    If needed, you can use an auxiliary function that
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Christian Urban <christian.urban@kcl.ac.uk> 
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    10  | 
//    performs the recursion. The function should expect
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Christian Urban <christian.urban@kcl.ac.uk> 
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    11  | 
//    arguments in the range of 1 to 1 Million.
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Christian Urban <christian.urban@kcl.ac.uk> 
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    12  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    13  | 
def collatz(n: Long) : Long = ???
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Christian Urban <christian.urban@kcl.ac.uk> 
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    14  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    15  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    16  | 
//(2) Complete the collatz_max function below. It should
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Christian Urban <christian.urban@kcl.ac.uk> 
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    17  | 
//    calculate how many steps are needed for each number 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    18  | 
//    from 1 up to a bound and then calculate the maximum number of
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Christian Urban <christian.urban@kcl.ac.uk> 
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    19  | 
//    steps and the corresponding number that needs that many 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    20  | 
//    steps. Again, you should expect bounds in the range of 1
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Christian Urban <christian.urban@kcl.ac.uk> 
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    21  | 
//    up to 1 Million. The first component of the pair is
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Christian Urban <christian.urban@kcl.ac.uk> 
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    22  | 
//    the maximum number of steps and the second is the 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    23  | 
//    corresponding number.
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Christian Urban <christian.urban@kcl.ac.uk> 
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    24  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    25  | 
def collatz_max(bnd: Long) : (Long, Long) = ???
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Christian Urban <christian.urban@kcl.ac.uk> 
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    26  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    27  | 
//(3) Implement a function that calculates the last_odd
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    28  | 
//    number in a collatz series.  For this implement an
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Christian Urban <christian.urban@kcl.ac.uk> 
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    29  | 
//    is_pow_of_two function which tests whether a number 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    30  | 
//    is a power of two. The function is_hard calculates 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    31  | 
//    whether 3n + 1 is a power of two. Again you can
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Christian Urban <christian.urban@kcl.ac.uk> 
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    32  | 
//    assume the input ranges between 1 and 1 Million,
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Christian Urban <christian.urban@kcl.ac.uk> 
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    33  | 
//    and also assume that the input of last_odd will not 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    34  | 
//    be a power of 2.
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Christian Urban <christian.urban@kcl.ac.uk> 
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    35  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    36  | 
def is_pow_of_two(n: Long) : Boolean = ???
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Christian Urban <christian.urban@kcl.ac.uk> 
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    37  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    38  | 
def is_hard(n: Long) : Boolean = ???
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Christian Urban <christian.urban@kcl.ac.uk> 
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    39  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    40  | 
def last_odd(n: Long) : Long = ???
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Christian Urban <christian.urban@kcl.ac.uk> 
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    41  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    42  | 
}
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Christian Urban <christian.urban@kcl.ac.uk> 
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    43  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    44  | 
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Christian Urban <christian.urban@kcl.ac.uk> 
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    45  | 
  |