Project Euler: Problem 8

The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832.

(see the number below)

Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. What is the value of this product?

Use NumPy for this computation



In [2]:

    
import numpy as np



In [3]:

    
d1000 = """73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450"""



In [10]:

    
g = list(d1000)
z=[]
for i in range(len(g)):
    if g[i] == 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 :
        z.append(g[i])
x = np.array((z), dtype = int)









    



---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-10-a6d5922b38e5> in <module>()
      4     if g[i] == 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 :
      5         z.append(g[i])
----> 6 x = np.array((z), dtype = int)

ValueError: invalid literal for int() with base 10: '\n'



In [58]:

    
g = list(d1000)
z=[]
for i in range(len(g)):
    if g[i] == 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 :
        z.append(g[i])
        


d = []
for i in range(len(z)):
    if z[i] == '1':
        d.append(1.0)
    elif z[i] == '2':
        d.append(2.0)
    elif z[i] == '3':
        d.append(3.0)
    elif z[i] == '4':
        d.append(4.0)
    elif z[i] == '5':
        d.append(5.0)
    elif z[i] == '6':
        d.append(6.0)
    elif z[i] == '7':
        d.append(7.0)
    elif z[i] == '8':
        d.append(8.0)
    elif z[i] == '9':
        d.append(9.0)
    else:
        d.append(0.0)

x = np.array(d)

print(x)









    



[ 7.  3.  1. ...,  4.  5.  0.]



In [6]:

    
g = list(d1000)
z=[]
for i in range(len(g)):
    if g[i] == 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 :
        z.append(g[i])
        


d = []
for i in range(len(z)):
    if z[i] == '1':
        d.append(1.0)
    elif z[i] == '2':
        d.append(2.0)
    elif z[i] == '3':
        d.append(3.0)
    elif z[i] == '4':
        d.append(4.0)
    elif z[i] == '5':
        d.append(5.0)
    elif z[i] == '6':
        d.append(6.0)
    elif z[i] == '7':
        d.append(7.0)
    elif z[i] == '8':
        d.append(8.0)
    elif z[i] == '9':
        d.append(9.0)
    else:
        d.append(0.0)

x = np.array(d)

products_13digit = []

for i in range(len(x)-13):
    products_13digit.append(x[i:i + 13].prod())
    
y = np.array(products_13digit).max()

print(y)

"""the printed number y is the answer"""









    



5377010688.0






    Out[6]:





'the printed number y is the answer'



In [ ]:



In [7]:

    
assert True # leave this for grading



In [ ]: