Project Euler Problem 52 Statement
It can be seen that the number, $125874$, and its double, $251748$, contain the same digits, but in a different order.
Find the smallest positive integer, $x$, such that $2x$, $3x$, $4x$, $5x$, and $6x$, contain the same digits.
Solution
The HackerRank version extends the original Project Euler problem by requiring us to find all numbers within a given constraint space where a number and its multiples (from $2x$ to $Kx$) are permutations of each other. To solve this, we employ a straightforward brute-force approach to systematically query each candidate.
Optimization with Divisibility by 9: We can safely start our search with $125874$ (as shown in the HackerRank problem statement) which is a multiple of $9$ and increment by $9$ for each query. Numbers that are permutations of each other always share the same digital root, which implies they are divisible by $9$.
By using the splat (*) operator to unpack argument lists, we can print the contents of a dynamically created list on a single line across the range of K results.
print(*[m*i for m in range(1, K+1)])HackerRank version
HackerRank Project Euler 52: Given $N$ (125875≤ N ≤ 2000000), find all the positive integers, $x≤ N$, such that $x, 2x, …, Kx (2≤ K ≤ 6)$ contain the same digits.
Python Source Code
N,K = map(int, input().split())
is_perm = lambda i,j:sorted(str(i))==sorted(str(j))
q = range(2, K+1)
for i in range(125874, N+1, 9):
if all(is_perm(i, m*i) for m in q):
print(*[m*i for m in range(1, K+1)]) Last Word
Project Euler 52 code:print (next(i for i in range(10, 1000000) if all(sorted(str(i)) == sorted(str(i*j)) for j in range(2, 7))))