Zigzag Array

Zigzag Array

Your function should create a list of lists, that represents a two-dimensional grid with the given number of rows and cols.

This grid should contain integers (int) from start to start + rows * cols - 1 in ascending order, but the elements of every odd-index row have to be listed in descending order, so that when read in ascending order, the numbers zigzag through the two-dimensional grid.

example

Input: Two integers (int) - rows and columns. One optional integer (int) - start.

Output: List of lists.

Examples:

assert create_zigzag(3, 5) == [[1, 2, 3, 4, 5], [10, 9, 8, 7, 6], [11, 12, 13, 14, 15]]
assert create_zigzag(5, 1) == [[1], [2], [3], [4], [5]]
assert create_zigzag(3, 3, 5) == [[5, 6, 7], [10, 9, 8], [11, 12, 13]]

The mission was taken from Python CCPS 109 Fall 2018. It is taught for Ryerson Chang School of Continuing Education by Ilkka Kokkarinen

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