C++/Size of a 2d vector

Question

How do I find the size of a 2 dimensional vector? So far I have the following code which doesn't compile.

#include <iostream> #include <vector>  using namespace std;  int main() {      vector < vector <int> > v2d;      for (int x = 0; x < 3; x++)     {         for (int y = 0; y < 5; y++)         {             v2d.push_back(vector <int> ());             v2d[x].push_back(y);         }     }      cout<<v2d[0].size()<<endl;     cout<<v2d[0][0].size()<<endl;      return 0; } 

Answer 1

To get the size of v2d, simply use v2d.size(). For size of each vector inside v2d, use v2d[k].size().

Note: for getting the whole size of v2d, sum up the size of each individual vector, as each vector has its own size.