Problem 43019. Iterative sum of digits of 2^n number
Given n, calculate the number 2^n (where n>=0) and iterate until the sum of the digits is a single-digit number.
Example:
Input n = 7
Output sum = 2
because 2^7 = 128, and 1+2+8=11 and 1+1=2.
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goc3
on 5 Oct 2016
I clarified the problem statement and fixed one test case to make the problem solvable as originally intended.
James
on 6 Oct 2016
Anyone else running into an issue with 2^111? I'm getting 2^111 = 2596148429267413814265248164610048, which sums to 143, which sums to 8. The test suite says 9.
Binbin Qi
on 11 Nov 2016
The last test is not correct. Could you check it ?
Jean-Marie Sainthillier
on 30 May 2017
Yes, this is a sequence (1 2 4 8 7 5 1 2 4 8 7 5 ...)
ChrisR
on 12 Jul 2021
The test with n = 111 is still incorrect.
Ramon Villamangca
on 27 Oct 2021
is should be 8 for n = 111. am I missing something?
goc3
on 12 Apr 2022
The last test case has been fixed.
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