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# 1329. Sort the Matrix Diagonally

<https://leetcode.com/problems/sort-the-matrix-diagonally>

## Description

A **matrix diagonal** is a diagonal line of cells starting from some cell in either the topmost row or leftmost column and going in the bottom-right direction until reaching the matrix's end. For example, the **matrix diagonal** starting from `mat[2][0]`, where `mat` is a `6 x 3` matrix, includes cells `mat[2][0]`, `mat[3][1]`, and `mat[4][2]`.

Given an `m x n` matrix `mat` of integers, sort each **matrix diagonal** in ascending order and return *the resulting matrix*.

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/01/21/1482_example_1_2.png)

```
**Input:** mat = [[3,3,1,1],[2,2,1,2],[1,1,1,2]]
**Output:** [[1,1,1,1],[1,2,2,2],[1,2,3,3]]
```

**Example 2:**

```
**Input:** mat = [[11,25,66,1,69,7],[23,55,17,45,15,52],[75,31,36,44,58,8],[22,27,33,25,68,4],[84,28,14,11,5,50]]
**Output:** [[5,17,4,1,52,7],[11,11,25,45,8,69],[14,23,25,44,58,15],[22,27,31,36,50,66],[84,28,75,33,55,68]]
```

**Constraints:**

* `m == mat.length`
* `n == mat[i].length`
* `1 <= m, n <= 100`
* `1 <= mat[i][j] <= 100`

## ac

```java
```