C++ Finding a integer value in a .txt file

Question

I have a map.txt file:

[Map]
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

[Details]
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0 
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

[Collision]
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0 
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 0 0 1 1 0 0 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 1 1 0 0 0 1 1 0 0 1 1 1 1 1 1 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

I also have a square on my screen that fills in the tile that my mouse has clicked on. The problem I have is I want to be able to edit the map.txt file by changing a value of it according to where on the map I click. I need to know if there is a way I can access a certain value in the map file, like an array. So for example getting Collision[5][8] or Details[7][17], etc. Thanks!

http://screencast.com/t/gqH18wgW (This shows the clicking to find the location)

Answer 1

While you could store the location in the file of each cell and overwrite individual cells, this only works if the old and new strings are the same length.

A more flexible and very straightforward way is to:

• Parse the file into an array. (see Read integers from a text file with C++ ifstream )
• Update the array whenever the user clicks.
• When finished, turn the array back into a file.