<p>You are given a <strong>0-indexed</strong> 2D matrix <code>grid</code> of size <code>m x n</code>, where <code>(r, c)</code> represents:</p>

<ul>
	<li>A <strong>land</strong> cell if <code>grid[r][c] = 0</code>, or</li>
	<li>A <strong>water</strong> cell containing <code>grid[r][c]</code> fish, if <code>grid[r][c] &gt; 0</code>.</li>
</ul>

<p>A fisher can start at any <strong>water</strong> cell <code>(r, c)</code> and can do the following operations any number of times:</p>

<ul>
	<li>Catch all the fish at cell <code>(r, c)</code>, or</li>
	<li>Move to any adjacent <strong>water</strong> cell.</li>
</ul>

<p>Return <em>the <strong>maximum</strong> number of fish the fisher can catch if he chooses his starting cell optimally, or </em><code>0</code> if no water cell exists.</p>

<p>An <strong>adjacent</strong> cell of the cell <code>(r, c)</code>, is one of the cells <code>(r, c + 1)</code>, <code>(r, c - 1)</code>, <code>(r + 1, c)</code> or <code>(r - 1, c)</code> if it exists.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2023/03/29/example.png" style="width: 241px; height: 161px;" />
<pre>
<strong>Input:</strong> grid = [[0,2,1,0],[4,0,0,3],[1,0,0,4],[0,3,2,0]]
<strong>Output:</strong> 7
<strong>Explanation:</strong> The fisher can start at cell <code>(1,3)</code> and collect 3 fish, then move to cell <code>(2,3)</code>&nbsp;and collect 4 fish.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2023/03/29/example2.png" />
<pre>
<strong>Input:</strong> grid = [[1,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,1]]
<strong>Output:</strong> 1
<strong>Explanation:</strong> The fisher can start at cells (0,0) or (3,3) and collect a single fish. 
</pre>

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

<ul>
	<li><code>m == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 10</code></li>
	<li><code>0 &lt;= grid[i][j] &lt;= 10</code></li>
</ul>

class Solution:
    def findMaxFish(self, grid: List[List[int]]) -> int:
        
        visited = set()
        def dfs(i, j):
            if min(i, j) < 0 or i >= len(grid) or j >= len(grid[0]) or grid[i][j] == 0 or (i, j) in visited:
                return 0
            visited.add((i, j))
            right = dfs(i, j+1)
            down = dfs(i+1, j)
            left = dfs(i, j-1)
            up = dfs(i-1, j)
            return right + down + left + up + grid[i][j]
        ans = float('-inf')
        for i in range(len(grid)):
            for j in range(len(grid[0])):
                if not (i, j) in visited:
                    print(i, j)
                    ans = max(ans, dfs(i, j))
        return ans
284