fill_n not working

Question

Hi

Please refer code below:

I have at the end of code added fill_n code lines but vector is not getting updated... Please suggest. Do I need to do push_back all the time and fill_n does not work this way?

https://code.sololearn.com/cd3ezhtwAqKI/?ref=app

Answer 1

What you really want is instead of using reserve(), you should use resize().

Reserve: https://cplusplus.com/reference/vector/vector/reserve/
Resize: https://cplusplus.com/reference/vector/vector/resize/

Answer 2

Yes, the reserve() does only change the max value of size, so the size doesn't change, if you try to fill_n more than the size it will not change the vector.

Answer 3

Thanks Tomás Ribeiro

It works as per my need with reset

I dont have to use fill_n also

Now my work is done but curious to know that whats the use of fill_n ? Does it work only on available elements and it cant add new elements alltogether ?
https://code.sololearn.com/cN0xHypY26lT/?ref=app