Vectors in C++

In C++, the push_back() function is used to add elements to the end of a dynamic array or vector. When working with a 2D vector, you can use push_back() to add rows and then use push_back() within each row to add elements to that row. Here's an example:

#include <iostream>
#include <vector>

int main() {
    // Declare a 2D vector
    std::vector<std::vector<int>> my2DVector;

    // Create the first row
    std::vector<int> row1;
    row1.push_back(1);
    row1.push_back(2);
    row1.push_back(3);

    // Create the second row
    std::vector<int> row2;
    row2.push_back(4);
    row2.push_back(5);
    row2.push_back(6);

    // Add rows to the 2D vector
    my2DVector.push_back(row1);
    my2DVector.push_back(row2);

    // Access and print elements of the 2D vector
    for (size_t i = 0; i < my2DVector.size(); ++i) {
        for (size_t j = 0; j < my2DVector[i].size(); ++j) {
            std::cout << my2DVector[i][j] << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}

In this example, row1 and row2 are two vectors representing two rows of a 2D vector. The push_back() function is used to add elements to each row. Then, these rows are added to the my2DVector using push_back().

You can continue to use this approach to add more rows or elements to the 2D vector as needed. Adjust the data types and values according to your specific requirements.

2d vectors