How to clear a matrix declared like this -> vector>

Question

I want a fast method to clear(set a matrix with 0 everywhere) a matrix of type vector<vector<int>>, just simple as the initialization was:

vector<vector<int>> values(nr_rows, vector<int>(nr_cols, 0));

Can I do this without a for?

IMO, you're probably starting from the wrong place. Is there a good reason you can't provide 2D addressing of a single vector instead? For example, see: http://stackoverflow.com/a/6465254/179910. With that as a starting point, it's pretty trivial to add a `clear` member function if you see fit (not necessarily a good idea, but easy anyway). — Jerry Coffin, Oct 13 '14 at 20:11
A first improvement would be continuous memory - as @JerryCoffin suggests — , Oct 13 '14 at 20:13
I have a signature of a function that I am not able to modify and it's vector> — Roxana Istrate, Oct 13 '14 at 21:12

Dark Falcon · Accepted Answer · 2014-10-13T20:09:55.303

1

values.assign(nr_rows, vector<int>(nr_cols, 0));

edited Oct 13 '14 at 20:09

answered Oct 13 '14 at 20:04

Dark Falcon

1 Answers1