Minimum Falling Path Sum

Given an `n x n` array of integers `matrix`, return _the **minimum sum** of any **falling path** through_ `matrix`. A **falling path** starts at any element in the first row and chooses the element in the next row that is either directly below or diagonally left/right. Specifically, the next element from position `(row, col)` will be `(row + 1, col - 1)`, `(row + 1, col)`, or `(row + 1, col + 1)`.   **Example 1:** **Input:** matrix = [[2,1,3],[6,5,4],[7,8,9]] **Output:** 13 **Explanation:** There are two falling paths with a minimum sum as shown. ``` **Example 2:** **Input:** matrix = [[-19,57],[-40,-5]] **Output:** -59 **Explanation:** The falling path with a minimum sum is shown. ```   **Constraints:** - `n == matrix.length == matrix[i].length` - `1 <= n <= 100` - `-100 <= matrix[i][j] <= 100`