How do I use 2D vectors in C++?

Can you show me some examples of using 2D vectors in C++?

Sure! In C++, you can use the std::vector to create a 2D vector. Here's a simple example:

#include <iostream>
#include <vector>

int main() {
    std::vector<std::vector<int>> vec(3, std::vector<int>(4, 0)); // 3 rows and 4 columns
    vec[0][1] = 5; // Set value at row 0, column 1
    std::cout << vec[0][1]; // Output: 5
    return 0;
}

What if I want to initialize it with specific values?

You can initialize a 2D vector with specific values like this:

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

How do I access elements in a 2D vector?

You can access elements using the syntax vec[row][column]. For example, vec[1][2] will give you the element in the second row and third column.

Can I resize a 2D vector after creating it?

Yes, you can resize a 2D vector using the resize method. For example:

vec.resize(4, std::vector<int>(5, 0)); // Resizes to 4 rows and 5 columns