KATHTHI  KATHTHI
Kathiresan is initially locked at cell (0,0) in a highly guarded rectangular prison of order RxC. He must reach the gate at (R1,C1) in order to escape from the prison. Kathiresan can move from any cell, to any of it's 4 adjacent cells (North, East, West and South). If Kathiresan is currently at (x1,y1), then he can move to (x2,y2) if and only if abs(x2x1)+abs(y2y1) == 1 and 0<=x2<R and 0<=y2<C
Kathiresan somehow manages to get the map of the prison.
If map[x1][y1] == map[x2][y2] then Kathiresan can move from (x1,y1) to (x2,y2) without killing any guards.
If map[x1][y1] != map[x2][y2], then Kathiresan can move from (x1,y1) to (x2,y2) by killing a guard.
Given the map of the prison, find the minimum number of guards Kathiresan must kill in order to escape from the prison.
Input:
The first line consists of an integer t, the number of test cases. For each test case, the first line consists of two integers R and C representing the order of the rectangular prison followed by R strings representing the map of the rectangular prison.
Output:
For each test case find the minimum number of guards Kathiresan must kill in order to escape from the prison.
Input Constraints:
1 <= t <= 10
2 <= R <= 1000
2 <= C <= 1000
'a' <= map[i][j] <= 'z'
Sample Input:
4
2 2
aa
aa
2 3
abc
def
6 6
akaccc
aaacfc
amdfcc
aokhdd
zyxwdp
zyxwdd
5 5
abbbc
abacc
aaacc
aefci
cdgdd
Sample Output:
0
3
2
2
hide comments
vee_nits123:
20200813 06:40:27
AC in one goes Yayy!!


budds_14:
20200626 09:51:26
Use 01 BFS to get the answer. 

shimul58:
20200607 08:59:04
Last edit: 20200607 20:36:05 

mubtasim91:
20200424 23:48:19
Can someone please review my Java submission https://ideone.com/I2hWsg ?


dkkv0000:
20200114 06:50:19
[spoiler] bfs learn it and apply it Last edit: 20200127 10:51:09 

sandeepd:
20191210 20:31:18
This is a great problem. Thanks @cegprakash! 

jitendra10099:
20191210 14:55:30
Is it possible to implement it with dynamic programming ? 

asad:
20190730 11:56:37
tried with [stop spoiling other people] Last edit: 20190930 14:45:33 

abhinav_jain02:
20190613 19:02:30
Learn about optimization of Dijkstra's algorithm for graphs having constrained weights. 

shivansh100:
20181203 09:48:45
getting TLE again and again :( 
Added by:  cegprakash 
Date:  20150116 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: BF 