Time Limit:3000ms Memory Limit:65536KB
Hot Spot is a single player game played on a 4 by 4 game board.
The purpose of the game is to move a red robot from its current
location on the board to the top left corner. The game board
may also contain green and blue robots. Each square of
the game board can be occupied by no more than one robot
at any time.
A robot may move in one of two ways:
- If two robots are adjacent
horizontally or vertically (but not diagonally), one of them
may jump over the other to the immediately adjacent square,
provided that square is empty.
For example, if robot a is immediately to the left of robot
b, robot a may jump to the square immediately to the right of
- If three robots are adjacent in a line (again not diagonally),
one of them may jump over the other two, provided the destination
square is empty. For example, if robot b is
immediately to the right of robot a and robot c is immediately to the
right of robot b, robot a may jump to the square immediately to the
right of robot c.
Every jump only changes the positions of the existing robots;
robots are never removed from or added to the game board.
A blue robot is never allowed to be adjacent horizontally
or vertically to another blue robot or to the red robot.
Given the initial configuration of the game board, determine
the minimum number of jumps required to move the red robot
into the top left corner.
The input specifies the initial position of the board using four lines,
each containing four characters. Each character may be either
R, indicating the red robot, B, indicating a blue robot, G, indicating
a green robot, or a period (.), indicating an empty square.
Output a single line containing a single integer,
the minimum number of jumps required for the red
robot to reach the top left square of the game board.
Output for Sample Input