Let f be a function that takes a string composed of a's, b's, and c's, and replaces every occurrence of 'a' with **arep**, 'b' with **brep**, and 'c' with **crep**. Your code will compute the length of (quotes for clarity): f( f( f( ... f(a) ... ) ) ) : f applied **iter** times to the string "a"
Since the lengths can grow very large with only a few iterations, you will return the length mod **m**.
For example, if
**arep** = abc
**brep** = c
**crep** = ba
**iter** = 3
**m** = 7
then you will find the length of
f(f(f(a))) = f(f(abc)) = f(abccba) = abccbabacabc ,
which is 12. Then you will compute 12 mod 7 = 5, and return 5. |