Python: Print a given N by M matrix of numbers line by line in forward > backwards > forward >... order

Python Basic - 1: Exercise-78 with Solution

Matrix Forward-Backward Printing

Write a Python program to print a given N by M matrix of numbers line by line in forward > backwards > forward >... order.

Input matrix:
[[1, 2, 3, 4],
[5, 6, 7, 8],
[0, 6, 2, 8],
[2, 3, 0, 2]]
Output:
1
2
3
4
8
7
6
5
0
6
2
8
2
0
3
2

Sample Solution:

Python Code:

# Define a function to print a matrix in a zigzag pattern
def print_matrix(nums):
    # Initialize a flag to determine the printing direction
    flag = True 
    
    # Iterate through each line in the matrix
    for line in nums:
        # Check the flag to determine the printing direction
        if flag == True: 
            # If flag is True, print the elements from left to right
            i = 0
            while i < len(line):
                print(line[i])
                i += 1
            # Update the flag for the next line
            flag = False
        else: 
            # If flag is False, print the elements from right to left
            i = -1
            while i > -1 * len(line) - 1:
                print(line[i])
                i = i - 1
            # Update the flag for the next line
            flag = True

# Test the function with a matrix and print the elements in a zigzag pattern
print_matrix([[1, 2, 3, 4],
              [5, 6, 7, 8],
              [0, 6, 2, 8],
              [2, 3, 0, 2]])

Sample Output:

1
2
3
4
8
7
6
5
0
6
2
8
2
0
3
2

Explanation:

Here is a breakdown of the above Python code:

• The function "print_matrix()" prints the elements of a matrix in a zigzag pattern.
• It initializes a flag ('flag') to determine the printing direction.
• It iterates through each line in the matrix ('nums').
• Depending on the flag, it either prints the elements from left to right or from right to left.
• After printing a line, it updates the flag for the next line.
• The function is tested with a sample matrix, and the elements are printed in a zigzag pattern.

Flowchart:

Python Code Editor:

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