diagonal-traverse-ii

Given a 2D integer array nums, return all elements of nums in diagonal order as shown in the below images.

Example 1:

Input: nums = [[1,2,3],[4,5,6],[7,8,9]]
Output: [1,4,2,7,5,3,8,6,9]

Example 2:

Input: nums = [[1,2,3,4,5],[6,7],[8],[9,10,11],[12,13,14,15,16]]
Output: [1,6,2,8,7,3,9,4,12,10,5,13,11,14,15,16]

Constraints:

• 1 <= nums.length <= 105


• 1 <= nums[i].length <= 105


• 1 <= sum(nums[i].length) <= 105


• 1 <= nums[i][j] <= 105