C++ Matrix Transpose Function Code Review and Optimization

C++ Matrix Transpose Function Code Review and Optimization

The following code snippet aims to implement a function for transposing a matrix in C++:

int** transposeMatrix(int **a, int row,int col){
    int** result = new int*[col];
    for(int i=0; i<row; i++){
        a[i] = new int[row];
    }
    for (int i = 0; i < row; ++i) {
        for (int j = 0; j < col; ++j) {
            result[i][j]=a[j][i];
        }
    }
    return result;

}

This code, however, contains several issues that need to be addressed:

Issue 1: Incorrect Memory Allocation

The code allocates memory for the rows of the result matrix using col instead of row. This results in incorrect memory allocation and potential problems during the transpose operation.

Issue 2: Segmentation Fault

The code attempts to access memory that is not allocated for the result matrix. This leads to a segmentation fault error, which is a serious runtime issue.

Recommendation

To fix these issues and implement a correct matrix transpose function, the code should be modified as follows:

int** transposeMatrix(int **a, int row, int col) {
    int** result = new int*[col];
    for (int i = 0; i < col; i++) {
        result[i] = new int[row];
    }
    for (int i = 0; i < row; ++i) {
        for (int j = 0; j < col; ++j) {
            result[j][i] = a[i][j];
        }
    }
    return result;
}

This corrected code allocates memory correctly for the rows of the result matrix and addresses the segmentation fault issue. It also ensures that the transpose operation is performed correctly.

This revised function demonstrates the importance of carefully allocating memory and avoiding memory access errors when working with dynamic data structures like matrices in C++.