Chain of powers

You have to program the function @short_power7_chains@ below. Remember
that 1 is a power of 7: 7⁰ = 1. The following auxiliar function may be
helpful.

    def is_power7(n):
        '''
        Requires a non negative integer n.
        Returns True when n is a power of 7
        Returns False when n is not a power of 7
        '''
        if n == 0:
            return False
        while n != 1:
            if n%7 != 0:
                return False
            n = n//7
        return True

- Write a function @short_power7_chains(f, k)@ that given a list f of
  non negative integers and an integer k greater than zero returns True
  when all the chains formed by powers of seven have size at most k;
  otherwise the function returns False. A chain of powers of seven is a
  block of consecutive numbers in the list all of them being a power of
  seven.

Scoring

The function counts 100 points.

Sample session

Problem information

Author: ProAl

Generation: 2026-01-25T19:33:35.731Z

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