2025-08-24 12:06:30 +0000 UTC

class Solution:
    def zigzagTraversal(self, grid: List[List[int]]) -> List[int]:
        m, n = len(grid), len(grid[0])
        res = []
        skip = False
        for row in range(m):
            if row % 2 == 0:
                start, end, step = 0, n, 1
            else:
                start, end, step = n - 1, -1, -1
            for col in range(start, end, step):
                if not skip:
                    res.append(grid[row][col])
                skip = not skip
        return res