how to resize a 2D vector?

[tinie]

How can I resize a 2D vector of int? initially i have declared vector<vector<int> > value;
I saw that

void resize(n, t = T())

should be used, but I can't seem to understand how it works. I want to initialize the added elements initialed to some integer value, say 1. how can I do that?

Thanks for the help.

[horace1]

How can I resize a 2D vector of int? initially i have declared vector<vector<int> > value;
I saw that

void resize(n, t = T())

should be used, but I can't seem to understand how it works. I want to initialize the added elements initialed to some integer value, say 1. how can I do that?

Thanks for the help.

you need to resize the vector and its elements, e.g.

#include <iostream>
#include <vector>
using namespace std;
 
int main()
{
  vector < vector < int > > value(5, vector <int>(10,0));
  cout << "value capacity " << value.capacity() << endl;
  for(int i=0; i<value.capacity();i++)
     cout << "  elment capacity " << (value.at(i)).capacity() << endl;
  // resize value
  value.resize(10, vector <int>(10,0));
  cout << "value capacity " <<  value.capacity() << endl;
  for(int i=0; i<value.capacity();i++)
     cout << "  elment capacity " << (value.at(i)).capacity() << endl;
  // resize element
  for(int i=0; i<value.capacity();i++)
     (value.at(i)).resize(20, 5);
  cout << "value capacity " <<  value.capacity() << endl;
  for(int i=0; i<value.capacity();i++)
     cout << "  elment capacity " << (value.at(i)).capacity() << endl;
  cin.get();
}