Project Euler 8

题目

Largest product in a series

The four adjacent digits in the \(1000\)-digit number that have the greatest product are \(9\times9\times8\times9=5832\).

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?

解决方案

需要将这个数字字符串矩阵复制出来，然后进行拼接。 最终将枚举每一个长度为\(13\)的子串的乘积即可。

代码

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

a = [int(x) for x in s.replace(" ", "")]
ans = 0
for i in range(len(a) - 13):
    m = 1
    for j in range(13):
        m *= a[i + j]
    ans = max(ans, m)
print(ans)