SICP Exercise 1.11

Exercise 1.11.  A function f is defined by the rule that f(n) = n if n<3 and f(n) = f(n - 1) + 2f(n - 2) + 3f(n - 3) if n> 3. Write a procedure that computes f by means of a recursive process. Write a procedure that computes f by means of an iterative process.

 Part 1: Recursive

 The code is here.

 Part 2: Iterative

 The code is here.

 Part 3: Tests

The tests and results are here.

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