<p>You are given a 2D matrix <code>grid</code> of size <code>n x n</code>. Initially, all cells of the grid are colored white. In one operation, you can select any cell of indices <code>(i, j)</code>, and color black all the cells of the <code>j<sup>th</sup></code> column starting from the top row down to the <code>i<sup>th</sup></code> row.</p>

<p>The grid score is the sum of all <code>grid[i][j]</code> such that cell <code>(i, j)</code> is white and it has a horizontally adjacent black cell.</p>

<p>Return the <strong>maximum</strong> score that can be achieved after some number of operations.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">grid = [[0,0,0,0,0],[0,0,3,0,0],[0,1,0,0,0],[5,0,0,3,0],[0,0,0,0,2]]</span></p>

<p><strong>Output:</strong> <span class="example-io">11</span></p>

<p><strong>Explanation:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2024/05/11/one.png" style="width: 300px; height: 200px;" />
<p>In the first operation, we color all cells in column 1 down to row 3, and in the second operation, we color all cells in column 4 down to the last row. The score of the resulting grid is <code>grid[3][0] + grid[1][2] + grid[3][3]</code> which is equal to 11.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">grid = [[10,9,0,0,15],[7,1,0,8,0],[5,20,0,11,0],[0,0,0,1,2],[8,12,1,10,3]]</span></p>

<p><strong>Output:</strong> <span class="example-io">94</span></p>

<p><strong>Explanation:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2024/05/11/two-1.png" style="width: 300px; height: 200px;" />
<p>We perform operations on 1, 2, and 3 down to rows 1, 4, and 0, respectively. The score of the resulting grid is <code>grid[0][0] + grid[1][0] + grid[2][1] + grid[4][1] + grid[1][3] + grid[2][3] + grid[3][3] + grid[4][3] + grid[0][4]</code> which is equal to 94.</p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;=&nbsp;n == grid.length &lt;= 100</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>0 &lt;= grid[i][j] &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution:
    def maximumScore(self, grid: List[List[int]]) -> int:
        n = len(grid)
        dp = [[0] * (n + 1)] + [[-inf] * (n + 1) for _ in range(n)]
        for col in range(1, n):
            temp = [[0] * (n + 1) for _ in range(n + 1)]
            for i in range(n + 1):
                total = 0
                maxPrefix = list(accumulate([dp[pre][i] for pre in range(n + 1)], max))
                maxSuffix = list(accumulate([dp[pre][i] for pre in range(n, -1, -1)], max))[::-1]
                for j in range(i, -1, -1):
                    temp[i][j] = maxPrefix[n] + total
                    total += grid[j - 1][col]
                for j in range(i + 1, n + 1):
                    maxPrefix[j] = max(maxPrefix[j], maxPrefix[j - 1] + grid[j - 1][col - 1])
                    temp[i][j] = max(maxPrefix[j], maxSuffix[j])
            dp = [row.copy() for row in temp]
        return max(max(row) for row in dp)
18400