Matrix Zig-Zag Traversal

Given an `N x M` matrix, print all elements in the zig-zag diagonal order shown by the statement. Requirements Input line 1 contains matrix_row and matrix_col. The next N lines contain M space-separated integers for the matrix. Print N * M space-separated integers representing the matrix in zig-zag order. The example traversal starts at the top-left, walks along anti-diagonals, and alternates direction by diagonal. Examples Input: 3 3 1 2 3 4 5 6 7 8 9 Output: 1 2 4 7 5 3 6 8 9 Notes The source names this as a LeetCode 53-style variant, but the prompt's shown order is anti-diagonal zig-zag rather than spiral order. Follow the screenshot's example order.