Hey Guys! :) C++ --> 20x20 Grid help!

[BrandiFranks]

I am needing help!! I don't really know whats going on but was told maybe some help on this forum would help... I don't know.. PLEASE HELP!!

'm solving Problem 11 from Project Euler. The grid is saved in a file project5.txt and its contents are-

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 question is- What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 20x20 grid?

It has to be written in C++ I need it to input the .txt file and output the highest 4 numbers and the sum!! PLEASE HELP!! Thanks love ya!

[laserlight]

What have you tried, or at least what idea/algorithm do you have in mind?

[BrandiFranks]

I understand the concept of the program but I guess I need some help starting?? I have been reading slowly about the input of the file but not really sure the full concept of it all..

[Alexandre]

This is maybe a tad advanced for you if you don't know how to read a file yet. There is a tutorial on this topic on this very website. Go check it out first.

[iMalc]

Okay, what you need to know to start it I guess is that you'll need to read all of the numbers into an array, perhaps a two-dimensional one and from there you'll be looping over various combinations of adjacent values looking for a maximum total.
You'll at least need to write something that reads the numbers into the array, and once you've either completed that or gotten very close to, then we may be able to assist further.

[AndrewHunter]

So, for a starting point you may want to read through:

• Lesson 3 - Loops
• Lesson 8 - Arrays
• Lesson 10 - File I/O

Additionally, unless you are required to use arrays for your class, it would be easier to implement this using std::vector and std::iterators.