ABCPATH - ABC Path

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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

hide comments
coder_hsnake: 2017-02-03 23:46:53

solved in one go using dp :D

imperfectboy: 2017-01-29 18:38:33

AC in one GO!!!

sandeep_4141: 2017-01-05 20:04:18

easy one ! use dfs !!

p_kr: 2016-11-04 06:58:25

if there is no 'A' ans should be 0, cost me 1 WA

prasoonbatham: 2016-10-22 07:09:34

Using excess stack memory in recursion resulted in TLE. Finally AC. :)

tni_mdixit: 2016-10-14 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: 2016-10-14 01:20:46

Careful of the case where no 'A' is present

madhavgaba: 2016-10-06 20:43:30

BFS:D

hamjosh1: 2016-09-10 22:19:32

Got 5 Wa because of wrongly taking the string input .-.

true_coder: 2016-09-05 14:16:00

note that max length of path is 26 ...stupid mistake...i was counting in cyclic manner from a->z->a


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