Python Program for Program to Print Matrix in Z form

Given a square matrix of order n × n, the task is to print its elements in Z form that is, print the first row, then the opposite diagonal (from top-right to bottom-left), and finally the last row of the matrix. For Example:

Input: [ [ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ] ]
Output: 1 2 3 5 7 8 9

Let's explore different methods to print the matrix in Z form in Python.

Using NumPy

This method uses NumPy’s advanced indexing to directly extract the first row, reverse diagonal, and last row in a single optimized line without explicit loops.

4 5 6 8 3 8 1 8 7 5

Explanation:

• m[0] first row and np.fliplr(m) flips matrix left to right.
• np.diag(...)[1:-1] extracts reverse diagonal excluding corners and m[-1] last row.
• * unpacks all elements for printing.

Using List Comprehension

This approach combines rows and diagonals in a single list using list comprehension. It collects all required elements in order and prints them together fast and clean without extra loops.

4 5 6 8 3 8 1 8 7 5

Explanation:

• arr[0] first row and [arr[i][n - i - 1] ...] collects reverse diagonal elements.
• arr[-1] last row and *res unpacks all values for clean printing.

Using Flattened Index Access

This method flattens the matrix into a single list and computes exact indices for the top row, diagonal, and bottom row, then prints those elements sequentially.

4 5 6 8 3 8 1 8 7 5

Explanation:

• flt = sum(arr, []) flattens the 2D matrix and range(n) top row indices.
• Second list reverse diagonal indices and Last list bottom row indices.
• Extract and print elements using computed indices.

Using Index-Based Traversal

This method uses nested loops to traverse each required position step by step first printing the top row, then the diagonal, and finally the bottom row in order.

4 5 6 8 3 8 1 8 7 5 

Explanation:

• First for loop: arr[0][j] prints elements of the top row left to right.
• Middle loop: for each row i from 1 to n-2, arr[i][n-i-1] computes the column index for the opposite diagonal and prints that element.
• Last for loop: arr[n-1][j] prints all elements of the bottom row.

Please refer complete article on Program to Print Matrix in Z form for more details!