<p>Given a 2D integer array <code>nums</code>, return <em>all elements of </em><code>nums</code><em> in diagonal order as shown in the below images</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/04/08/sample_1_1784.png" style="width: 158px; height: 143px;" />
<pre>
<strong>Input:</strong> nums = [[1,2,3],[4,5,6],[7,8,9]]
<strong>Output:</strong> [1,4,2,7,5,3,8,6,9]
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/04/08/sample_2_1784.png" style="width: 230px; height: 177px;" />
<pre>
<strong>Input:</strong> nums = [[1,2,3,4,5],[6,7],[8],[9,10,11],[12,13,14,15,16]]
<strong>Output:</strong> [1,6,2,8,7,3,9,4,12,10,5,13,11,14,15,16]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i].length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= sum(nums[i].length) &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i][j] &lt;= 10<sup>5</sup></code></li>
</ul>

class Solution:
    def findDiagonalOrder(self, nums: List[List[int]]) -> List[int]:
        m, n = len(nums), max([len(num) for num in nums])
        total = n + m - 1
        res = [[] for _ in range(total)]
        for i in range(m):
            for j in range(len(nums[i])):
                res[i+j].append(nums[i][j])  
        ans = []
        for num in res:
            ans.extend(num[::-1])
        return ans













        # res = []
        # for k in range(total):
        #     if k >= m:
        #         i,j = m-1,k-(m-1)
        #     else:
        #         i,j = k,0

        #     path = []
        #     while 0<=i<m and 0<=j<n:
        #         if j<len(nums[i]):
        #             path.append(nums[i][j])
        #         i-=1
        #         j+=1
        #     res.extend(path)

        # return res

















        # m, n = len(nums), max([len(num) for num in nums])
        # total = n + m -1

        # res = []
        # for k in range(total):
        #     if k >= m:
        #         i,j = m-1,k-(m-1)
        #     else:
        #         i,j = k,0

        #     path = []
        #     while 0<=i<m and 0<=j<n:
        #         if j<len(nums[i]):
        #             path.append(nums[i][j])
        #         i-=1
        #         j+=1
        #     res.extend(path)

        # return res
37098