Created
April 11, 2018 11:57
-
-
Save kylethedeveloper/bc5fd68df97af9fa828386a433ebfdea to your computer and use it in GitHub Desktop.
Project Euler - Problem 8 - Largest product in a series
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/* | |
Project_8.cpp : 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? | |
*/ | |
#include <iostream> | |
#include <fstream> | |
#include <vector> | |
using namespace std; | |
int main() | |
{ | |
size_t size = 1000; //size of array 1000 | |
vector<int> num(size); //dynamic array | |
ifstream inFile; | |
inFile.open("number.txt"); //open the file | |
if (inFile.is_open()) | |
{ | |
char n1; | |
int n, i = 0; | |
while (inFile.get(n1)) // reading every char in file | |
{ | |
if (n1 != 10) // as there are "line feed" (\n), we exclude that | |
{ | |
n = n1 - 48; // converting char to int | |
num[i] = n; // assigning digits to the array | |
i++; | |
} | |
} | |
} | |
else | |
cerr << "Error opening file!" << endl; | |
inFile.close(); | |
long long greatest = 0; // type is long long as it can exceed int range | |
for (int i = 0; i < 988; i++) // imagine num[987+12] = num[999] | |
{ | |
long long temp = 1; // same reason | |
for (int j = 0; j < 13; j++) | |
{ | |
temp *= num[i + j]; // multiplying 13 adjacent digits | |
} | |
if (temp > greatest) | |
{ | |
greatest = temp; | |
} | |
} | |
cout << "Greatest product of thirteen adjacent digits is " << greatest << endl; | |
return 0; | |
} | |
// HELL OF A PROBLEM! | |
// TOOK ME 3/2 HOURS TO SOLVE BUT IT'S WORTH IT !!! |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment