1289 - Minimum Falling Path Sum II.

Hard

Given an n x n integer matrix grid, return the minimum sum of a falling path with non-zero shifts.

A falling path with non-zero shifts is a choice of exactly one element from each row of grid such that no two elements chosen in adjacent rows are in the same column.

Example 1:

Input: arr = [1,2,3,4,5,6,7,8,9]

Output: 13

Explanation: The possible falling paths are: 1,5,9, 1,5,7, 1,6,7, 1,6,8, 2,4,8, 2,4,9, 2,6,7, 2,6,8, 3,4,8, 3,4,9, 3,5,7, 3,5,9 The falling path with the smallest sum is 1,5,7, so the answer is 13.

Example 2:

Input: grid = [7]

Output: 7

Constraints:

• n == grid.length == grid[i].length

• 1 <= n <= 200

• -99 <= grid[i][j] <= 99