Removing Elements from a 2D Vector

Dec 2, 2015 at 4:34pm

Hello,

I am writing a program for a Sudoku puzzle using Constraint Satisfaction. I have created a 2D vector to store the domains of possible values:

vector<vector<int>> domains;

The 2D vector is in a struct.

Long story short, the domains are filled with 0 values, and I need to remove any instance of the elements that are equal to 0. How do I remove an element in a 2D array?

 for(int i = 0; i < mainBoard.domains.size(); i++)
    {
        if(!mainBoard.isFixedValue[i])
        {
            for(int j = 0; j < 9; j++)
            {
                if(mainBoard.domains[i][j] == 0)
                {
                  mainBoard.domains[i].erase(mainBoard.domains[j].begin() + j);
                }
            }
        }
    }

Edit & Run

When I do this, the program crashes during runtime with an error:

Cygwin_exception::open_stackdumpfile: Dumping stack trace to Soduku2.exe.stackdump

PLEASE HELP!!

Last edited on Dec 2, 2015 at 4:34pm

Dec 2, 2015 at 5:51pm

jlb (4973)

Why that magic number 9?

What happens when you erase the first element (how many elements do you have left)?

Dec 2, 2015 at 6:10pm

gambler2841 (2)

The 9 is because there is a maximum number of 9 values that can be stored as domain values, 1-9 (possible Sudoku values). I suppose I could have the limit be the size of mainBoard.domains[i].size(). Let me see what happens, or if it succeeds, when I delete the beginning element.

Last edited on Dec 2, 2015 at 6:14pm

Dec 2, 2015 at 6:16pm

jlb (4973)

Yes but why are you using this constant in a for() loop that removes elements? If you erase one elements you will only have 8 elements in the vector. If you then try to access the 9^th element you will be accessing the vector out of range.

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Removing Elements from a 2D Vector

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