(Problem) 008 Largest product in a series

작성일 In 댓글:

Project Euler

  • 공식 홈페이지 - projecteuler.net
  • 한글 번역 - projecteuler @kr
  • (HackerRank) ProjectEuler+ - hackerrank.com

Problem

Largest product in a series


problem <번역>

solution

Simple Code

모든 경우의 수를 다 비교하는 코드

008_largest_product_in_a_series.py
from functools import reduce


strNum = "73167176531330624919225119674426574742355349194934\
96983520312774506326239578318016984801869478851843\
85861560789112949495459501737958331952853208805511\
12540698747158523863050715693290963295227443043557\
66896648950445244523161731856403098711121722383113\
62229893423380308135336276614282806444486645238749\
30358907296290491560440772390713810515859307960866\
70172427121883998797908792274921901699720888093776\
65727333001053367881220235421809751254540594752243\
52584907711670556013604839586446706324415722155397\
53697817977846174064955149290862569321978468622482\
83972241375657056057490261407972968652414535100474\
82166370484403199890008895243450658541227588666881\
16427171479924442928230863465674813919123162824586\
17866458359124566529476545682848912883142607690042\
24219022671055626321111109370544217506941658960408\
07198403850962455444362981230987879927244284909188\
84580156166097919133875499200524063689912560717606\
05886116467109405077541002256983155200055935729725\
71636269561882670428252483600823257530420752963450"


def largest_product_in_a_series(bigNum):
  maxProduct = 1
  length = len(bigNum)

  for num in range(0, length):
      product = reduce(lambda x, y: int(x) * int(y), bigNum[num:num + 13])

      if int(product) > maxProduct:
          maxProduct = product

  return maxProduct


bigNum = strNum.replace(' ', '')
print(largest_product_in_a_series(bigNum))
HackerRank

위 코드를 그대로 사용하면 Runtime Error가 뜨기 때문에 조금의 리팩토링을 했다

008_for_HacerRank.py
from functools import reduce


def largest_product_in_a_series(bigNum, k):
  maxProduct = 0
  length = len(bigNum)

  for num in range(length - k):
      maxProduct = max(maxProduct, reduce(lambda x, y: x * y, bigNum[num:num + k]))

  return maxProduct


if __name__ == '__main__':
  for _ in range(int(input())):
      N, K = map(int, input().split())
      strNum = input().strip()
      bigNum = [int(x) for x in strNum]

      print(largest_product_in_a_series(bigNum, K))

0을 마주쳤을 때, 특정 범위(HackerRank기준, K) 만큼 건너뛰는 방식을 취하면 조금이나마 성능 향상이 있을 것 같다