Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- /************************************************
- Programmer : Muhammad Azri bin Jasni @ Abdul Rani
- Program : project euler problem 11_2.cpp
- Link : http://projecteuler.net/problem=11
- Description: Finally got the answer
- Note : Diagonally, means both left-to-right and right-to-left.
- *************************************************
- In the 20×20 grid below, four numbers along a diagonal line have been marked in red.
- 08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
- 49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
- 81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
- 52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
- 22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
- 24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
- 32 98 81 28 64 23 67 10 [26] 38 40 67 59 54 70 66 18 38 64 70
- 67 26 20 68 02 62 12 20 95 [63] 94 39 63 08 40 91 66 49 94 21
- 24 55 58 05 66 73 99 26 97 17 [78] 78 96 83 14 88 34 89 63 72
- 21 36 23 09 75 00 76 44 20 45 35 [14] 00 61 33 97 34 31 33 95
- 78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
- 16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
- 86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
- 19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
- 04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
- 88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
- 04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
- 20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
- 20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
- 01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48
- The product of these numbers is 26 × 63 × 78 × 14 = 1788696.
- What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 20×20 grid?
- ************************************************/
- /*
- Draft
- 1. put in 2-dimensional array
- 2. get max product of 4 adjacent numbers for diogonally, horizontaly and vertically (three for-loop)
- 3. test with small sample:
- 08 02 22 97
- 49 49 99 40
- 81 49 31 73
- 52 70 95 23
- 08 09 are octal form, cant be used for int?? huh?
- horizontal and vertical was done using trial and error... so I don't remember
- diagonal test
- [0][0] [1][1] [2][2] [3][3] , [0][1] [1][2] [2][3] [3][4]
- [1][0] [2][1] [3][2] [4][3] , [1][1] [2][2] [3][3] [4][4]
- for (int i=0;i<max-3;i++)
- for (int j=0;j<max-3;j++)
- [i][j]*[i+1][j+1]*[i+2][j+2]*[i+3][j+3]
- we may reduce process by identify 0. bcoz 0 will result in zero, so can skip instantly if want
- */
- /*
- Thanks to this page: http://blog.functionalfun.net/2008/05/project-euler-problem-11.html
- Although, there is C++ solution, that person calculate diagonal 2 times more than needed.
- ***************
- diagonal test [right to left]
- [0][3] [1][2] [2][1] [3][0] , [0][4] [1][3] [2][2] [3][1]
- [1][3] [2][2] [3][1] [4][0] , [1][4] [2][3] [3][2] [4][1]
- for (int i=0;i<max-3;i++)
- for (int j=3;j<max;j++)
- [i][j]*[i+1][j-1]*[i+2][j-2]*[i+3][j-3]
- */
- #include <iostream>
- using namespace std;
- bool checkZero(int);
- int main ()
- {
- const int max = 20;
- long maxProduct = 0;//greatest product
- long product = 1;
- //initialize array
- int numbers [max][max] =
- {
- { 8,02,22,97,38,15,00,40,00,75,04,05,07,78,52,12,50,77,91, 8},
- {49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,04,56,62,00},
- {81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,03,49,13,36,65},
- {52,70,95,23,04,60,11,42,69,24,68,56,01,32,56,71,37,02,36,91},
- {22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80},
- {24,47,32,60,99,03,45,02,44,75,33,53,78,36,84,20,35,17,12,50},
- {32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70},
- {67,26,20,68,02,62,12,20,95,63,94,39,63, 8,40,91,66,49,94,21},
- {24,55,58,05,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72},
- {21,36,23, 9,75,00,76,44,20,45,35,14,00,61,33,97,34,31,33,95},
- {78,17,53,28,22,75,31,67,15,94,03,80,04,62,16,14, 9,53,56,92},
- {16,39,05,42,96,35,31,47,55,58,88,24,00,17,54,24,36,29,85,57},
- {86,56,00,48,35,71,89,07,05,44,44,37,44,60,21,58,51,54,17,58},
- {19,80,81,68,05,94,47,69,28,73,92,13,86,52,17,77,04,89,55,40},
- {04,52, 8,83,97,35,99,16,07,97,57,32,16,26,26,79,33,27,98,66},
- {88,36,68,87,57,62,20,72,03,46,33,67,46,55,12,32,63,93,53,69},
- {04,42,16,73,38,25,39,11,24,94,72,18, 8,46,29,32,40,62,76,36},
- {20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,04,36,16},
- {20,73,35,29,78,31,90,01,74,31,49,71,48,86,81,16,23,57,05,54},
- {01,70,54,71,83,51,54,69,16,92,33,48,61,43,52,01,89,19,67,48}
- };
- //horizontal
- for (int i=0; i<(max); i++)
- {
- for (int j=0; j<(max-3); j++)
- {
- if (checkZero(numbers[i][j]))
- continue;
- product = numbers[i][j] * numbers[i][j+1] * numbers[i][j+2] * numbers[i][j+3];
- //cout << numbers[i][j] << "*" << numbers[i][j+1] << "*" << numbers[i][j+2]<< "*" << numbers[i][j+3] << "=" << product <<endl;//test
- if (product > maxProduct)
- maxProduct = product;
- }
- }
- //cout << "===========" << endl; //test
- //vertical
- for (int j=0; j<(max); j++)
- {
- for (int i=0; i<(max-3); i++)
- {
- if (checkZero(numbers[i][j]))
- continue;
- product = numbers[i][j] * numbers[i+1][j] * numbers[i+2][j] * numbers[i+3][j];
- //cout << numbers[i][j] << "*" << numbers[i+1][j] << "*" << numbers[i+2][j] << "*" << numbers[i+3][j] << "=" << product <<endl;//test
- if (product > maxProduct)
- maxProduct = product;
- }
- }
- //cout << "===========" << endl; //test
- //diagonal left to right
- for (int i=0; i<(max-3); i++)
- {
- for (int j=0; j<(max-3); j++)
- {
- if (checkZero(numbers[i][j]))
- continue;
- product = numbers[i][j] * numbers[i+1][j+1] * numbers[i+2][j+2] * numbers[i+3][j+3];
- //cout << numbers[i][j] << "*" << numbers[i+1][j+1] << "*" << numbers[i+2][j+2] << "*" << numbers[i+3][j+3] << "=" << product <<endl;//test
- if (product > maxProduct)
- maxProduct = product;
- }
- }
- //diagonal right to left
- for (int i=0; i<(max-3); i++)
- {
- for (int j=3; j<(max); j++)
- {
- if (checkZero(numbers[i][j]))
- continue;
- product = numbers[i][j] * numbers[i+1][j-1] * numbers[i+2][j-2] * numbers[i+3][j-3];
- //cout << numbers[i][j] << "*" << numbers[i+1][j+1] << "*" << numbers[i+2][j+2] << "*" << numbers[i+3][j+3] << "=" << product <<endl;//test
- if (product > maxProduct)
- maxProduct = product;
- }
- }
- // cout << "===========" << endl; //test
- cout << "maxProduct = " << maxProduct << endl;
- //system("pause");
- return 0;
- }
- bool checkZero(int a)
- {
- if (a==0)
- return true;
- else
- return false;
- }
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement