#MLASERP. Laser Phones
Laser Phones
| English | Vietnamese |
The cows have a new laser-based system so they can have casual
conversations while out in the pasture which is modeled as a W x H
grid of points (1 <= W <= 100; 1 <= H <= 100).
The system requires a sort of line-of-sight connectivity in order
to sustain communication. The pasture, of course, has rocks and
trees that disrupt the communication but the cows have purchased
diagonal mirrors ('/' and '\' below) that deflect the laser beam
through a 90 degree turn. Below is a map that illustrates the
problem.
H is 8 and W is 7 for this map. The two communicating cows are
notated as 'C's; rocks and other blocking elements are notated as
'*'s:
7 . . . . . . . 7 . . . . . . .
6 . . . . . . C 6 . . . . . /-C
5 . . . . . . * 5 . . . . . | *
4 * * * * * . * 4 * * * * * | *
3 . . . . * . . 3 . . . . * | .
2 . . . . * . . 2 . . . . * | .
1 . C . . * . . 1 . C . . * | .
0 . . . . . . . 0 . \-------/ .
0 1 2 3 4 5 6 0 1 2 3 4 5 6
Determine the minimum number of mirrors M that must be installed
to maintain laser communication between the two cows, a feat which
is always possible in the given test data.
INPUT
* Line 1: Two space separated integers: W and H * Lines 2..H+1: The entire pasture. SAMPLE INPUT 7 8 ....... ......C ......* *****.* ....*.. ....*.. .C..*.. .......
OUTPUT
* Line 1: A single integer: M SAMPLE OUTPUT 3
Any suggestted testcase will be welcomed.