Normal Initialisation of 3D Vector

Normal Initialization of 3D Vector in C++

To initialize a 3D vector in C++, you can follow these steps:

  1. Include the necessary header file: Before using the vector class, you need to include the <vector> header file in your source code. This file provides the necessary definitions and functions for working with vectors.

  2. Declare the vector: Declare a variable of type vector<vector<vector<T>>>, where T is the type of the elements you want to store in the vector. This declaration creates an empty vector.

  3. Set the size of the vector: Use the resize() function to set the size of the vector. The resize() function takes the desired size as its argument and resizes the vector accordingly. For example, to create a 3D vector with dimensions x, y, and z, you would use the following code:

cpp vector<vector<vector<T>>> myVector; myVector.resize(x, vector<vector<T>>(y, vector<T>(z)));

This code resizes the vector to have x elements in the first dimension, each containing a vector with y elements in the second dimension, each containing a vector with z elements in the third dimension. The T() part initializes each element with a default-initialized value of type T.

  1. Access and modify the elements: You can access and modify the elements of the 3D vector using the usual indexing syntax. For example, to access the element at position (i, j, k), you would use myVector[i][j][k].

Here is an example that demonstrates the normal initialization of a 3D vector in C++:

#include <vector>

int main() {
    int x = 3;
    int y = 4;
    int z = 5;

    // Declare and resize the 3D vector
    std::vector<std::vector<std::vector<int>>> myVector;
    myVector.resize(x, std::vector<std::vector<int>>(y, std::vector<int>(z)));

    // Access and modify the elements
    myVector[1][2][3] = 42;

    return 0;
}

This example creates a 3D vector with dimensions 3, 4, and 5, and assigns the value 42 to the element at position (1, 2, 3).