WATER  Water among Cubes
On a rectangular mesh comprising n*m fields, n*m cuboids were put, one cuboid on each field. A base of each cuboid covers one field and its surface equals to one square inch. Cuboids on adjacent fields adhere one to another so close that there are no gaps between them. A heavy rain pelted on a construction so that in some areas puddles of water appeared.
Task
Write a program which:
 reads from the standard input a size of the chessboard and heights of cuboids put on the fields,
 computes maximal water volume, which may gather in puddles after the rain,
 writes results in the standard output.
Input
The number of test cases t is in the first line of input, then t test cases follow separated by an empty line. In the first line of each test case two positive integers 1 <= n <= 100, 1 <= m <= 100 are written. They are the size of the mesh. In each of the following n lines there are m integers from the interval [1..10000]; ith number in jth line denotes a height of a cuboid given in inches put on the field in the ith column and jth raw of the chessboard.
Output
Your program should write for each tes case one integer equal to the maximal volume of water (given in cubic inches), which may gather in puddles on the construction.
Example
Sample input: 1 3 6 3 3 4 4 4 2 3 1 3 2 1 4 7 3 1 6 4 1 Sample output: 5
The picture below shows the mesh after the rain (seen from above). Puddles are drawn in gray.
hide comments
ayush5148:
20170102 22:40:08
Finally AC after 7 days............start from the minimum height and then to the maximum height......


suraj_:
20161021 20:57:58
Finally AC !!!!!!! my 46th. @crypt is right


Aayush Sharda:
20160912 12:12:34
@crypt shouldn't the answer for your mentioned test case be 76. 

Sarthak Munshi:
20160815 13:27:00
This problem requires a very advance thought process . :p AC after 3 days . 

misawa:
20160730 09:54:32
great problem :) 

buttman:
20160513 20:56:35
bfs/dfs doesn't get any better than this :) 

RAMSDEN:
20160402 19:41:56
n^2 log(n) dijkshtra :) 

minhthai:
20160402 09:29:21
very nice logic, thanks :) 

Aseem Raj Baranwal:
20151001 15:32:11
Last edit: 20160202 10:39:17 

Rishabh:
20150611 01:09:16
Awesome Problem ! Last edit: 20150611 09:08:13 
Added by:  Piotr Łowiec 
Date:  20040913 
Time limit:  7s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: NODEJS PERL6 VB.NET 
Resource:  6th Polish Olympiad in Informatics, stage 3 