MAKEMAZE  VALIDATE THE MAZE
MAZE MAKING
There are many algorithms to generate maze. (http://en.wikipedia.org/wiki/Maze_generation_algorithm). After generating the maze we’ve to validate whether it’s a valid maze or not. A valid maze has exactly one entry point and exactly one exit point (exactly 2 openings in the edges) and there must be atleast one path from the entry point to exit point.
Given a maze, just find whether the maze is "valid" or "invalid".
Input Specification:
The first line consists of an integer t, the number of test cases. Then for each test case, the first line consists of two integers m and n, the number of rows and columns in the maze. Then contains the description of the matrix M of order mxn. M[i][j]=# represents a wall and M[i][j]='.' represents a space.
Output Specification:
For each test case find whether the maze is "valid" or "invalid".
Input Constraints:
1<=t<=10000
1<=m<=20
1<=n<=20
Sample Input:
6 4 4 #### #... #.## #.## 5 5 #.### #..## ##..# #.#.# ###.# 1 1 . 5 1 # # . . # 2 2 #. .# 3 4 #..# #.## #.##
Sample Output:
valid valid invalid valid invalid invalid
hide comments
Kumar Mrinal:
20131212 23:21:48
piece of cake :D 

god_father:
20131212 23:21:48
easy one ;got Ac in first Attempt.. 

ravi teja:
20131212 23:21:48
plz check submission id: 839598


Aditya Pande:
20131212 23:21:48
m getting WA for my submission


gabber:
20131212 23:21:48
is this valid?


Sardar Khan:
20131212 23:21:48
simple graph problem 

npsabari:
20131212 23:21:48
easy one! 

Aradhya:
20131212 23:21:48
goodness me :D in input there is a apace btw two characters.. but actually it is nt so.. got too many wrng answers for that misconception.. be careful :D 

Simón Murillo Gómez:
20131212 23:21:48
@himanshu jain is invalid


himanshu jain:
20131212 23:21:48
is this case a valid case?

Added by:  cegprakash 
Date:  20120511 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 GOSU 