1000자리 숫자에서, 연속하는 13자리숫자들의 곱중에서 가장 큰값을 찾는 문제입니다.
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?
1. 데이터불러오고,
2. 루프문을 만들고 13자리 곱을 계산하고,
3. 조건문으로 큰값을 판별해줍니다.
데이터 불러오기 -1
여러줄의 문자열은 작은따옴표 3개로 묶어주면 됩니다.
string='''73167176531330624919225119674426574742355349194934 96983520312774506326239578318016984801869478851843 85861560789112949495459501737958331952853208805511 12540698747158523863050715693290963295227443043557 66896648950445244523161731856403098711121722383113 62229893423380308135336276614282806444486645238749 30358907296290491560440772390713810515859307960866 70172427121883998797908792274921901699720888093776 65727333001053367881220235421809751254540594752243 52584907711670556013604839586446706324415722155397 53697817977846174064955149290862569321978468622482 83972241375657056057490261407972968652414535100474 82166370484403199890008895243450658541227588666881 16427171479924442928230863465674813919123162824586 17866458359124566529476545682848912883142607690042 24219022671055626321111109370544217506941658960408 07198403850962455444362981230987879927244284909188 84580156166097919133875499200524063689912560717606 05886116467109405077541002256983155200055935729725 71636269561882670428252483600823257530420752963450''' print(string)
73167176531330624919225119674426574742355349194934 96983520312774506326239578318016984801869478851843 85861560789112949495459501737958331952853208805511 12540698747158523863050715693290963295227443043557 66896648950445244523161731856403098711121722383113 .....
그러나 실제 변수안에 저장되는 문자열은 줄바꿈 문자(＼n)가 포함된 상태입니다.
string
'73167176531330624919225119674426574742355349194934\n96983520312774506326239578318016984801869478851843\n85861560789112949495459501737958331952853208805511\n12540698747158523863050715693290963295227443043557\n66896648950445244523161731856403098711121722383113\n
그래서 replace 명령으로 '＼n'을 '' 공백으로 치환해주면 됩니다.
string.replace('\n','')
73167176531330624919225119674426574742355349194934969835203127745063262395783180169848018694788518438
데이터 불러오기 -2
with open("q008_data.txt") as file_object:
lines = file_object.readlines()
string=''
for line in lines:
string=string+line.rstrip()
print(string)
731671765313306249192251...............................0823257530420752963450
또는 텍스트 파일에다 저장한후에 불러올수도 있습니다. (파일불러오기 토픽 참조)
연속 13자리 숫자 출력
for i in range(0,1000):
print(string[i:i+13])
7316717653133 3167176531330 1671765313306 6717653133062 7176531330624 1765313306249 7653133062491 ... .. .
문자열 slice 기능을 이용해서 13자리씩 끊어서 출력합니다.
연속 13자리 숫자 곱
for i in range(0,1000):
product =1
for j in string[i:i+13]:
product = product * int(j)
print(string[i:i+13],product)
7316717653133 5000940 3167176531330 0 1671765313306 0 6717653133062 0 7176531330624 0 1765313306249 0 7653133062491 0 6531330624919 0 ... ...
반복문을 사용해서 13자리를 곱합니다. 0 이 있는 경우는 결과가 0으로 계산됩니다.
13자리 숫자 곱(2)
from functools import reduce
for i in range(0,1000):
product = reduce(lambda x,y:int(x)*int(y), string[i:i+13])
print(string[i:i+13],product)
7316717653133 5000940 3167176531330 0 1671765313306 0 6717653133062 0 7176531330624 0 1765313306249 0 7653133062491 0 6531330624919 0 5313306249192 0 3133062491922 0 1330624919225 0 3306249192251 0 3062491922511 0 0624919225119 0 6249192251196 4199040 2491922511967 4898880 4919225119674 9797760 9192251196744 9797760 ... ..
아니면 5번 문제에서 사용한 reduce 함수를 사용해도 됩니다.
최대값
maxValue =0
for i in range(0,1000):
product =1
for j in string[i:i+13]:
product = product * int(j)
if product > maxValue:
maxValue = product
print(string[i:i+13],product, maxValue)
print(maxValue)
7316717653133 5000940 5000940 3167176531330 0 5000940 1671765313306 0 5000940 6717653133062 0 5000940 7176531330624 0 5000940 1765313306249 0 5000940 7653133062491 0 5000940 6531330624919 0 5000940 5313306249192 0 5000940 3133062491922 0 5000940 1330624919225 0 5000940 3306249192251 0 5000940 3062491922511 0 5000940 0624919225119 0 5000940 6249192251196 4199040 5000940 2491922511967 4898880 5000940 ... ... ... 23514624000
