The Lakes

3000ms

262144K

Description:

You are given an $$$n \times m$$$ grid $$$a$$$ of non-negative integers. The value $$$a_{i,j}$$$ represents the depth of water at the $$$i$$$-th row and $$$j$$$-th column.

A lake is a set of cells such that:

each cell in the set has $$$a_{i,j} > 0$$$, and
there exists a path between any pair of cells in the lake by going up, down, left, or right a number of times and without stepping on a cell with $$$a_{i,j} = 0$$$.

The volume of a lake is the sum of depths of all the cells in the lake.

Find the largest volume of a lake in the grid.

Input:

The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases.

The first line of each test case contains two integers $$$n, m$$$ ($$$1 \leq n, m \leq 1000$$$) — the number of rows and columns of the grid, respectively.

Then $$$n$$$ lines follow each with $$$m$$$ integers $$$a_{i,j}$$$ ($$$0 \leq a_{i,j} \leq 1000$$$) — the depth of the water at each cell.

It is guaranteed that the sum of $$$n \cdot m$$$ over all test cases does not exceed $$$10^6$$$.

Output:

For each test case, output a single integer — the largest volume of a lake in the grid.

Sample Input:

Sample Output:

Informação

Provedor Codeforces

Código CF1829E