• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
HarriPellikka

Searching horizontal / vertical lines in 2D arrays

4 posts in this topic

Heya,

I've got a bit of a problem that I can't figure out. I have 2D arrays of arbitrary sizes, and they contain characters like 'a', 'b', 'c' and so on. I need to break the arrays down into individual horizontal and vertical lines of the same characters, while a single character is only in one "partial array."

For example, let's concider this array:
[code]

0 1 2 3 4 . . .
0 a a a a a
1 a
2 a a a a
3 a
4 a
.
.
[/code]

Now, the result I want would be something like this:

[code]

Array 1:
0 1 2 3 4
0 a a a a a
1
2
3
4

Array 2:
0 1 2 3 4
0
1 a
2 a
3 a
4 a

Array 3:
0 1 2 3 4
0
1
2 a a a
3
4
[/code]

These arrays would of course be converted into coordinate lists for smaller memory. I've tried to think through this for a while, but can't really find any practical ways to do so. Any help is appreciated. [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img]
0

Share this post


Link to post
Share on other sites
Loop through every row counting how many equal 'a's you have found. Remember the maximum so far and where it was. Do the same thing column by column. Now take the place where the maximum was achieved, write down the corresponding line and remove it from the data. Rinse, repeat.

This might not be very fast, but it will at least serve as a basic implementation to get you going. You can speed it up a lot by remembering the places where you found the longest rows. Also, your example doesn't allow me to tell if you are OK describing a cross as two lines, or if you would rather describe it as one column and two rows, because you don't want to repeat the intersection. In any case, there are ways to make the process fast and I am sure you'll find them.
1

Share this post


Link to post
Share on other sites
[quote name='alvaro' timestamp='1332011427' post='4922863']
Loop through every row counting how many equal 'a's you have found. Remember the maximum so far and where it was. Do the same thing column by column. Now take the place where the maximum was achieved, write down the corresponding line and remove it from the data. Rinse, repeat.

This might not be very fast, but it will at least serve as a basic implementation to get you going. You can speed it up a lot by remembering the places where you found the longest rows. Also, your example doesn't allow me to tell if you are OK describing a cross as two lines, or if you would rather describe it as one column and two rows, because you don't want to repeat the intersection. In any case, there are ways to make the process fast and I am sure you'll find them.
[/quote]

The speed is not important since it won't be done runtime. The cross would indeed be one column and two rows (or vice versa), because a single char can only be part of a single line.

I didn't quite understand your suggestion, but it may just be my awful after-flu-stupidity and tiredness, hopefully I'll get it clear tomorrow with a bright mind. :D
0

Share this post


Link to post
Share on other sites
Something like this:
[code]#include <iostream>

bool get_longest_line(char array[5][5], int &x, int &y, int &dx, int &dy, int &length) {
length = 0;
for (int j=0; j<5; ++j) {
int current_length = 0;
for (int i=0; i<5; ++i) {
current_length = array[j][i] == 'a' ? current_length+1 : 0;
if (current_length > length) {
length = current_length;
x = i-length+1;
y = j;
dx = 1;
dy = 0;
}
else
current_length = 0;
}
}
for (int i=0; i<5; ++i) {
int current_length = 0;
for (int j=0; j<5; ++j) {
current_length = array[j][i] == 'a' ? current_length+1 : 0;
if (current_length > length) {
length = current_length;
x = i;
y = j-length+1;
dx = 0;
dy = 1;
}
}
}
return length > 0;
}

int main () {
char array[5][5] = {
{'a','a','a','a','a'},
{' ','a',' ',' ',' '},
{' ','a','a','a','a'},
{' ','a',' ',' ',' '},
{' ','a',' ',' ',' '}
};

int x, y, dx, dy, length;

while (get_longest_line(array, x, y, dx, dy, length)) {
std::cout << '(' << x << ',' << y << ") d=("
<< dx << ',' << dy << ')' << length << '\n';
for (int i=0; i<length; ++i)
array[y+i*dy][x+i*dx] = ' ';
}
}
[/code]
1

Share this post


Link to post
Share on other sites
Gee, thanks for the code! I also got some advice from Daniweb, which will produce even distribution for horizontal and vertical segments. Thank :)
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0