// Create a vector containing n
//vectors of size m, all u=initialized with 0
vector<vector<int> > vec( n , vector<int> (m, 0)); #include <bits/stdc++.h>
using namespace std;
int main()
{
int rows = 2;
int cols = 2;
int val = 1;
vector< vector<int> > v(rows, vector<int> (cols, val)); /*creates 2d vector “v[rows][cols]” and initializes all elements to “val == 1” (default value is 0)*/
v[0][0] = 5;
v[1][1] = 4;
cout << v[0][0] << endl; //Output: 5cout << v[1][0] << endl; //Output: 1return 0;}vector<vector<int>> v(row,vector<int>(col,val));// Initializing 2D vector "vect" with
// values
vector<vector<int> > vect{ { 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 } };