CPP

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));  

2d array using vector

// 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;
}

create a 2d vector in c++

// 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;
}

how to create 2d array using vector in c++

vector<vector<int>> vec(N, vector<int> (M, INT_MAX));

Explanation::
vector<vector<int>> -- will take the formed container
N -- Think like row of 2d Matrix
vector<int> (M, INT_MAX) -- In each row, there is again a vector associated with it, 
that will formed 2d array.