Transposing a Matrix in Java

Hello there! Are you ready to enhance your Java programming skills with another exciting exercise? In this unit, we are plunging into the world of matrices. More specifically, we'll be transposing a given matrix. Let's dive into this matrix manipulation game without delay!

To begin, let's elaborate on the task at hand. You are required to write a Java function named transformMatrix(). This function will accept a 2D int array (which represents a matrix) that contains integers as inputs. Your responsibility is to return another 2D int array, which is the transposed version of the given matrix.

Remember, when we mention 'transposing a matrix,' we are referring to the process of switching its rows and columns. In other words, all the rows of the original matrix should convert into columns in the transposed matrix, and vice versa.

For instance, if the original matrix (input 2D array) is:

int[][] matrix = {
    {1, 2, 3},
    {4, 5, 6}
};

Then the transposed matrix (output 2D array) will be:

int[][] transposed = {
    {1, 4},
    {2, 5},
    {3, 6}
};

It is vital for your result to maintain the integrity of the data type that is present in the original matrix. In layman's terms, the values seen in the input matrix are integers, and they should be integers in the output matrix as well.

The initial step of building our solution involves determining the dimensions of the matrix. We need to know the number of rows and columns present in it. In Java, the array length properties can offer this information. The number of rows is simply the length of the outer array, and the number of columns matches the length of any of the inner arrays.

class Solution {

    public static int[][] transformMatrix(int[][] matrix) {
        int rows = matrix.length;
        int cols = rows > 0 ? matrix[0].length : 0;
        // If rows > 0, the above line sets cols to
        // length of the first row, else sets to 0
    }
}

The subsequent step is to create a "placeholder" for the transposed matrix that is in alignment with its required dimensions. This will be a new 2D array, but with the number of rows and columns swapped. Initially, we can populate this matrix with all zeros.

class Solution {

    public static int[][] transformMatrix(int[][] matrix) {
        int rows = matrix.length;
        int cols = rows > 0 ? matrix[0].length : 0;
        int[][] result = new int[cols][rows];
    }
}