GO Classes 2023 | Weekly Quiz 4 | Question: 21

Answer 1

Here, => means prints.

mystery3(0) => null

mystery3(1) => null

mystery3(2) => mystery3(0) 2 mystery3(1) => 2

mystery3(3) => mystery3(1) 3 mystery3(2) => 32

mystery3(4) => mystery3(2) 4 mystery3(3) => 2432

mystery3(5) => mystery3(3) 5 mystery3(4) => 3252432

mystery3(6) => mystery3(4) 6 mystery3(5) => 243263252432 (answer)

Answer 2

Answer is 243263252432

Let the function mystery3() be represented as m() for ease. And printf() be represented as p().

Then we create a recursion tree (as shown).

• For right side of the tree we can reuse the output produced by the same function calls. Like 2432 is produced by mystery3(4)
• The function mystery3() simply returns when n=0 and when n=1

Answer 3

Assuming Mystery3() function as M and printf function as P .

Asterisk is made to reuse the value of function without making extra tree.