// Create a vector containing n
//vectors of size m, all u=initialized with 0
vector<vector<int> > vec( n , vector<int> (m, 0)); myVector[
Vector[0, 4, 2, 5],
Vector[1, 4, 2]
];
/*When you call for myVector[1].size() it would return 3 and [0] would return 4.
For the amount of rows (int vectors) in the 2d vector, you can just use myVector.size()
You can run this to see it in actions*/// CPP program
#include <iostream>
#include <vector>
using namespace std;
int main()
{
int n = 4;
int m = 5;
/*
Create a vector containing "n"
vectors each of size "m".
*/
vector<vector<int>> vec( n , vector<int> (m));
for(int i = 0; i < n; i++)
{
for(int j = 0; j < m; j++)
{
vec[i][j] = j + i + 1;
}
}
for(int i = 0; i < n; i++)
{
for(int j = 0; j < m; j++)
{
cout << vec[i][j] << " ";
}
cout << endl;
}
return 0;
}// CPP program
#include <iostream>
#include <vector>
using namespace std;
int main()
{
int n = 3;
int m = 4;
/*
We create a 2D vector containing "n"
elements each having the value "vector<int> (m, 0)".
"vector<int> (m, 0)" means a vector having "m"
elements each of value "0".
Here these elements are vectors.
*/
vector<vector<int>> vec( n , vector<int> (m, 0));
for(int i = 0; i < n; i++)
{
for(int j = 0; j < m; j++)
{
cout << vec[i][j] << " ";
}
cout<< endl;
}
return 0;
}// finding size of a square matrix
myVector[0].size();