ABCPATH  ABC Path
You will be given a 2dimensional grid of letters. Find the length of the longest path of consecutive letters, starting at 'A'. Paths can step from one letter in the grid to any adjacent letter (horizontally, vertically, or diagonally).
For example, in the following grid, there are several paths from 'A' to 'D', but none from 'A' to 'E':
One such path is:
Input
Each test case will start with a line contains two integers H, W the height and width of the grid respectively 1 <= H, W <= 50. Then H lines follow each of W uppercase letters only. Input terminates with H = 0 and W = 0.
Output
For each test case print “Case C: X” without quotes where C is the case number starting with 1 and X is the solution.
Example
Sample Input: 4 3 ABE CFG BDH ABC 0 0 Sample Output: Case 1: 4
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sandeep_4141:
20170105 20:04:18
easy one ! use dfs !! 

p_kr:
20161104 06:58:25
if there is no 'A' ans should be 0, cost me 1 WA 

prasoonbatham:
20161022 07:09:34
Using excess stack memory in recursion resulted in TLE. Finally AC. :) 

tni_mdixit:
20161014 15:49:20
simple recursion always works. :) at first i thought it would run out of time but careful observation leaves us with only 2 cases :D


sriraj:
20161014 01:20:46
Careful of the case where no 'A' is present 

madhavgaba:
20161006 20:43:30
BFS:D 

hamjosh1:
20160910 22:19:32
Got 5 Wa because of wrongly taking the string input .. 

true_coder:
20160905 14:16:00
note that max length of path is 26 ...stupid mistake...i was counting in cyclic manner from a>z>a 

realrefo31:
20160905 12:01:33
BEAST 

geekhamza:
20160822 08:04:53
take care of visiting a point two time, start dfs when you find 'A' and be carfull about inbound function , it caused me 3 WA 
Added by:  Ali Arous 
Date:  20111105 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  FCIS Local Contest 2012 