CPP

initialize 2d vector as 0

vector<vector<bool>> visited(n, vector<bool> (n, 0));

initialize 2d vector of ints c++

auto M = 4;	// num of rows
auto N = 3; // num of cols in each row
auto default_value = 1; // default value of all int elements
std::vector<std::vector<int>> matrix(M, std::vector<int>(N, default_value));

initializing 2d vector

// to make (n rows x m columns) 2D array, all initialized 
// with value 'k' (typeof(k) = T)
vector<vector<T>> vec( n , vector<T> (m, k)); 

initialize 2D vector

vector<vector<int> >    v2(8, vector<int>(5));

initialising 2d vector

// Initializing 2D vector "vect" with 
// values 
vector<vector<int> > vect{ { 1, 2, 3 }, 
                           { 4, 5, 6 }, 
                           { 7, 8, 9 } };