How do I create a 2D vector in C++?

How do I create a 2D vector in C++?

You can create a 2D vector in C++ using std::vector like this: std::vector<std::vector<int>> vec(rows, std::vector<int>(cols));

Can you give me an example of initializing it with values?

Sure! Here's an example: std::vector<std::vector<int>> vec = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; This initializes a 3x3 vector.

How do I access elements in this 2D vector?

You can access elements using the syntax vec[row][col]. For example, vec[1][2] will give you the value 6.

What if I want to change a value?

You can change a value by assigning a new value like this: vec[0][1] = 10; This will change the element at row 0, column 1 to 10.