题目
Given a 2D integer array nums, return all elements of nums in diagonal order as shown in the below images.
解题思路
i+j相同的格的数放在一行，从第一行开始遍历，由于从左下到右上，结果将每组翻转
代码
class Solution:
def findDiagonalOrder(self, nums: List[List[int]]) -> List[int]:
maxij = 0
tmp = defaultdict(list)
for i in range(len(nums)):
for j in range(len(nums[i])):
tmp[i + j].append(nums[i][j])
maxij = max(maxij, i + j)
res = []
for i in range(maxij + 1):
res.extend(tmp[i][::-1])
return res
