Problem 8(Largest product in a series)

Problem 8(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?

In Python:

arr=[]
arr=str('73167176531330624919225119674426574742355349194934'
        '96983520312774506326239578318016984801869478851843'
        '85861560789112949495459501737958331952853208805511'
        '12540698747158523863050715693290963295227443043557'
        '66896648950445244523161731856403098711121722383113'
        '62229893423380308135336276614282806444486645238749'
        '30358907296290491560440772390713810515859307960866'
        '70172427121883998797908792274921901699720888093776'
        '65727333001053367881220235421809751254540594752243'
        '52584907711670556013604839586446706324415722155397'
        '53697817977846174064955149290862569321978468622482'
        '83972241375657056057490261407972968652414535100474'
        '82166370484403199890008895243450658541227588666881'
        '16427171479924442928230863465674813919123162824586'
        '17866458359124566529476545682848912883142607690042'
        '24219022671055626321111109370544217506941658960408'
        '07198403850962455444362981230987879927244284909188'
        '84580156166097919133875499200524063689912560717606'
        '05886116467109405077541002256983155200055935729725'
        '71636269561882670428252483600823257530420752963450')

multiple=1

for i in range(0,987):
    temp=1
    for j in range(0,13):
        temp = temp * int(arr[i+j])
    if temp > multiple:
        multiple = temp

print(multiple)

Run time: 0.008214235305786133  seconds

In Java:

// Euler8 Largest product in a series

package project_euler;

import java.io.BufferedReader;

import java.io.FileReader;

import java.io.IOException;

public class Euler8 {

public static String readFile() throws IOException {

String numString = "";

//stream

BufferedReader numbers = new BufferedReader (new FileReader("./Euler8_number.txt"));

while (true) {

String line = numbers.readLine();

if (line == null) break;

numString += line;

}

numbers.close();

return numString;

}

public static void main(String[] args) throws IOException {

        long startTime = System.currentTimeMillis();

String numString = readFile();

int num = 0;

double maxProduct = 0;

double product = 1;

for (int i = 0; i < numString.length() - 12; i++) {

for (int j = 0; j < 13; j++) {

num = Integer.parseInt(numString.substring(i + j, i + j + 1));

product *= num;

}

if (product > maxProduct) {

maxProduct = product;

}

product = 1;

}

System.out.println(maxProduct);

long endTime = System.currentTimeMillis();

System.out.println((double)(endTime - startTime)/(double)1000 + "seconds");

}

}

Run time: 0.014seconds

solution: 23514624000

[from Project Euler: https://projecteuler.net/problem=8]