finding size of columns and rows in 2d vector c++

Code to find size of columns and rows in 2D vector in C++

#include <iostream>
#include <vector>

int main() {
    std::vector<std::vector<int>> matrix = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };

    int rows = matrix.size();
    int columns = matrix[0].size();

    std::cout << "Number of rows: " << rows << std::endl;
    std::cout << "Number of columns: " << columns << std::endl;

    return 0;
}

Explanation

1. Include the necessary headers for input-output stream and vectors.
2. Define the main function.
3. Create a 2D vector "matrix" and initialize it with some values.
4. Get the number of rows in the matrix using matrix.size().
5. Get the number of columns in the matrix by accessing the size of the first row matrix[0].size().
6. Output the number of rows and columns to the console.