numericpattern134.py

def generate_pattern(rows=5):
    """
    Generate a pattern dynamically where:
    - Odd rows (1st, 3rd, 5th...): Increment normally
    - Even rows (2nd, 4th...): Fill in reverse order at the end

    Example for 5x5:
    Row 1: 1-5    (block 0)
    Row 2: 11-15  (block 2)
    Row 3: 21-25  (block 4)
    Row 4: 16-20  (block 3)
    Row 5: 6-10   (block 1)
    """
    pattern = []

    odd_rows = (rows + 1) // 2
    even_rows = rows // 2# Number of even-positioned rows

    block_order = []
    for i in range(odd_rows):
        block_order.append(i * 2)

    for i in range(even_rows - 1, -1, -1):
        block_order.append(i * 2 + 1)

    for block in block_order:
        row = []
        start = block * rows + 1
        for j in range(rows):
            row.append(start + j)
        pattern.append(row)

    return pattern


def print_pattern(pattern):
    """Print the pattern in a formatted grid"""
    for row in pattern:
        print(' '.join(f'{num:3d}' for num in row))

n = int(input())
pattern = generate_pattern(n)
print_pattern(pattern)