Example: Transpose Dynamic Matrix using Pointers in C

// Transpose Dynamic Matrix using Pointers
#include <stdio.h>
#include <stdlib.h> // Required for malloc and free

// Function to allocate memory for a dynamic matrix
int** allocateMatrix(int rows, int cols) {
    int** matrix = (int**)malloc(rows * sizeof(int*));
    if (matrix == NULL) {
        perror("Failed to allocate memory for rows");
        exit(EXIT_FAILURE);
    }
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
        if (matrix[i] == NULL) {
            perror("Failed to allocate memory for columns");
            // Free previously allocated rows
            for (int k = 0; k < i; k++) {
                free(matrix[k]);
            }
            free(matrix);
            exit(EXIT_FAILURE);
        }
    }
    return matrix;
}

// Function to free memory of a dynamic matrix
void freeMatrix(int** matrix, int rows) {
    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
    }
    free(matrix);
}

// Function to print a dynamic matrix
void printDynamicMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d\t", matrix[i][j]);
        }
        printf("\n");
    }
}

// Function to transpose a dynamic matrix
void transposeDynamicMatrix(int** original, int** transposed, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            // original[i][j] becomes transposed[j][i]
            transposed[j][i] = original[i][j];
        }
    }
}

int main() {
    // Step 1: Define original matrix dimensions
    int rows = 2;
    int cols = 3;

    // Step 2: Allocate memory for original and transposed matrices
    int** originalMatrix = allocateMatrix(rows, cols);
    int** transposedMatrix = allocateMatrix(cols, rows); // Transposed will be cols x rows

    // Step 3: Initialize original matrix (example data)
    int count = 1;
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            originalMatrix[i][j] = count++;
        }
    }

    printf("Original Matrix (%dx%d):\n", rows, cols);
    printDynamicMatrix(originalMatrix, rows, cols);

    // Step 4: Transpose the matrix
    transposeDynamicMatrix(originalMatrix, transposedMatrix, rows, cols);

    printf("\nTransposed Matrix (%dx%d):\n", cols, rows);
    printDynamicMatrix(transposedMatrix, cols, rows);

    // Step 5: Free allocated memory
    freeMatrix(originalMatrix, rows);
    freeMatrix(transposedMatrix, cols);

    return 0;
}