Answers for "vector of vector"

how to make a 2d vector in c++

// Create a vector containing n 
//vectors of size m, all u=initialized with 0
vector<vector<int> > vec( n , vector<int> (m, 0));

get values from a vector of vectors c++

#include <iostream>
#include <vector>
using namespace std;  

int main()
{
    vector<vector<int> > buff;

    for(int i = 0; i < 10; i++)
    {
        vector<int> temp; // create an array, don't work directly on buff yet.
        for(int j = 0; j < 10; j++)
            temp.push_back(i); 
 
        buff.push_back(temp); // Store the array in the buffer
    }

    for(int i = 0; i < buff.size(); ++i)
    {
        for(int j = 0; j < buff[i].size(); ++j)
            cout << buff[i][j];
        cout << endl;
    }

    return 0;
}

vector of vectors c++

#include <iostream> 
#include <vector> 
using namespace std; 
  
int main() 
{ 
	int n = 5;
	int m = 7;
	//Create a vector containing n vectors of size m and initalize them to 0.
	vector<vector<int>> vec(n, vector<int>(m, 0));

	for (int i = 0; i < vec.size(); i++) //print them out
	{
		for (int j = 0; j < vec[i].size(); j++)
		{
			cout << vec[i][j] << " ";
		}
		cout << endl;
	}
}

vector of vectors c++

vector<vector<int>> matrix(x, vector<int>(y));

This creates x vectors of size y, filled with 0's.

vector of vectors c++

vector<vector<data_type>> vec;