# Largest product in a series # # The four adjacent digits in the 1000-digit number that # have the greatest product are 9 × 9 × 8 × 9 = 5832. # # 73167176531330624919225119674426574742355349194934 # 96983520312774506326239578318016984801869478851843 # 85861560789112949495459501737958331952853208805511 # 12540698747158523863050715693290963295227443043557 # 66896648950445244523161731856403098711121722383113 # 62229893423380308135336276614282806444486645238749 # 30358907296290491560440772390713810515859307960866 # 70172427121883998797908792274921901699720888093776 # 65727333001053367881220235421809751254540594752243 # 52584907711670556013604839586446706324415722155397 # 53697817977846174064955149290862569321978468622482 # 83972241375657056057490261407972968652414535100474 # 82166370484403199890008895243450658541227588666881 # 16427171479924442928230863465674813919123162824586 # 17866458359124566529476545682848912883142607690042 # 24219022671055626321111109370544217506941658960408 # 07198403850962455444362981230987879927244284909188 # 84580156166097919133875499200524063689912560717606 # 05886116467109405077541002256983155200055935729725 # 71636269561882670428252483600823257530420752963450 # # Find the thirteen adjacent digits in the 1000-digit # number that have the greatest product. What is the # value of this product? # # https://projecteuler.net/problem=8 import numpy as np str = ''' 73167176531330624919225119674426574742355349194934 96983520312774506326239578318016984801869478851843 85861560789112949495459501737958331952853208805511 12540698747158523863050715693290963295227443043557 66896648950445244523161731856403098711121722383113 62229893423380308135336276614282806444486645238749 30358907296290491560440772390713810515859307960866 70172427121883998797908792274921901699720888093776 65727333001053367881220235421809751254540594752243 52584907711670556013604839586446706324415722155397 53697817977846174064955149290862569321978468622482 83972241375657056057490261407972968652414535100474 82166370484403199890008895243450658541227588666881 16427171479924442928230863465674813919123162824586 17866458359124566529476545682848912883142607690042 24219022671055626321111109370544217506941658960408 07198403850962455444362981230987879927244284909188 84580156166097919133875499200524063689912560717606 05886116467109405077541002256983155200055935729725 71636269561882670428252483600823257530420752963450 ''' nlist = list(''.join(str.strip().split('\n'))) nlist = list(map(int, nlist)) # test adj_digits = 4 max_product = 0 for i in range(len(nlist)): if (i + adj_digits > len(nlist)): break product = np.prod(nlist[i:i+adj_digits]) if product > max_product: max_product = product assert(max_product == 5832) # solution adj_digits = 13 max_product = 0 for i in range(len(nlist)): if (i + adj_digits > len(nlist)): break product = np.prod(nlist[i:i+adj_digits]) if product > max_product: max_product = product print(max_product) # 23514624000