Answers for "c++ create 2d array"

2d array c++

int a[2][3]= {
        {1, 2, 3},
        {4, 5, 6}
    };
    
    cout << a[1][1]; // Output is 5

c++ code to write 2d array

#include <iostream>
using namespace std;
int main(){
	int n,m;
	int a[n][m];
	cin >> n >>m;
	for ( int i=0; i<n; i++){
		for (int j=0; j<m; j++){
			cin >> a[i][j];
		}
	}
	
	for ( int x=0; x<n; x++){
		for (int y=0; y<m; y++){
			cout << "a[" << x << "][" << y << "]: ";
			cout << a[x][y] << 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.