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`