ABCPATH - ABC Path

You will be given a 2-dimensional 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':

ABC

One such path is:

path

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

Added by:Ali Arous
Date:2011-11-05
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64
Resource:FCIS Local Contest 2012

hide comments
2019-05-20 19:06:51
dont go back to A after Z caused me 2 WAs . :(
2019-04-18 22:10:08
please anyone can tell me that how to apply dfs in this problem
2019-04-04 15:22:46
AC in one go


Last edit: 2019-04-04 15:57:12
2019-01-14 09:11:03
Didn't use memo and got 2 TLEs. Then AC
2018-12-26 18:08:22
DP on graphs.easily solvable in O(n*m) complexity.
2018-11-05 16:50:43
Simple DFS, AC in one go! :)
2018-10-21 09:08:18
BFS and DFS both work just fine! good problem to practice both
2018-10-11 20:38:04
recursion +memoisation
2018-09-16 08:29:43
Nice question I started with recursion and optimized it to multisource bfs. Got a lot of TLEs in between
2018-09-09 19:30:29
AC in one go !!
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