Problem 60181. Integer Persistence, Product
Solution Stats
Problem Comments
-
3 Comments
Test cases 4,8,9 and 10 have some incorrect values.
I don't understand where the error is.
For example, for test 4, we have the sequence $u_0 = 97$, $u_1 = 9 \times 7 = 63$, $u_2 = 6 \times 3 = 18$, $u_3 = 1 \times 8 = 8$, so $n = 3$. So, the sequence for test case 4 is 97→63→18→8 and n=3 since it took 3 steps to reach a single-digit number from 97.
Similarly, for test 8 (with a randomly chosen number from the given list): $u_0$ in L and $u_1<10$ (the elements of L are chosen so that the product of the digits always gives a number < 10).
Sorry, that was my error! I had written my code to do addition rather than multiplication, and in many, but not all, cases that gave the same result for the persistence.
Solution Comments
Show commentsProblem Recent Solvers9
Suggested Problems
-
8876 Solvers
-
4066 Solvers
-
3358 Solvers
-
376 Solvers
-
287 Solvers
More from this Author53
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!