Example: Matrix Transpose using Class in C++

// Matrix Transpose using Class
#include <iostream>

class Matrix {
private:
    int rows;
    int cols;
    int** data; // Pointer to an array of pointers (for dynamic 2D array)

public:
    // Constructor: Initializes matrix dimensions and allocates memory
    Matrix(int r, int c) : rows(r), cols(c) {
        data = new int*[rows]; // Allocate memory for row pointers
        for (int i = 0; i < rows; ++i) {
            data[i] = new int[cols]; // Allocate memory for columns in each row
        }
    }

    // Destructor: Deallocates memory to prevent memory leaks
    ~Matrix() {
        for (int i = 0; i < rows; ++i) {
            delete[] data[i]; // Delete columns for each row
        }
        delete[] data; // Delete row pointers
    }

    // Method to read elements into the matrix
    void readElements() {
        std::cout << "Enter matrix elements (" << rows << "x" << cols << "):" << std::endl;
        for (int i = 0; i < rows; ++i) {
            for (int j = 0; j < cols; ++j) {
                std::cout << "Enter element at (" << i + 1 << "," << j + 1 << "): ";
                std::cin >> data[i][j];
            }
        }
    }

    // Method to display the matrix
    void displayElements() {
        std::cout << "Matrix (" << rows << "x" << cols << "):" << std::endl;
        for (int i = 0; i < rows; ++i) {
            for (int j = 0; j < cols; ++j) {
                std::cout << data[i][j] << "\t";
            }
            std::cout << std::endl;
        }
    }

    // Method to display the transpose of the matrix
    void displayTranspose() {
        std::cout << "Transpose of Matrix (" << cols << "x" << rows << "):" << std::endl;
        for (int j = 0; j < cols; ++j) { // Iterate through columns of original matrix
            for (int i = 0; i < rows; ++i) { // Iterate through rows of original matrix
                std::cout << data[i][j] << "\t"; // Access element [row][col]
            }
            std::cout << std::endl;
        }
    }
};

int main() {
    int r, c;

    // Step 1: Get matrix dimensions from the user
    std::cout << "Enter number of rows: ";
    std::cin >> r;
    std::cout << "Enter number of columns: ";
    std::cin >> c;

    // Step 2: Create a Matrix object
    Matrix myMatrix(r, c);

    // Step 3: Read elements into the matrix
    myMatrix.readElements();

    // Step 4: Display the original matrix
    myMatrix.displayElements();

    // Step 5: Display the transpose of the matrix
    myMatrix.displayTranspose();

    return 0;
}