public class Solution
extends Object
329 - Longest Increasing Path in a Matrix\.
Hard
Given an `m x n` integers `matrix`, return _the length of the longest increasing path in_ `matrix`.
From each cell, you can either move in four directions: left, right, up, or down. You **may not** move **diagonally** or move **outside the boundary** (i.e., wrap-around is not allowed).
**Example 1:**
**Input:** matrix = \[\[9,9,4],[6,6,8],[2,1,1]]
**Output:** 4
**Explanation:** The longest increasing path is `[1, 2, 6, 9]`.
**Example 2:**
**Input:** matrix = \[\[3,4,5],[3,2,6],[2,2,1]]
**Output:** 4
**Explanation:** The longest increasing path is `[3, 4, 5, 6]`. Moving diagonally is not allowed.
**Example 3:**
**Input:** matrix = \[\[1]]
**Output:** 1
**Constraints:**
* `m == matrix.length`
* `n == matrix[i].length`
* `1 <= m, n <= 200`
* 0 <= matrix[i][j] <= 231 - 1