ZOJ Problem Set - 1354
In an extended version of the game Lights Out , is a puzzle with 5 rows of 6 buttons each (the actual puzzle has 5 rows of 5 buttons each). Each button has a light. When a button is pressed, that button and each of its (up to four) neighbors above, below, right and left, has the state of its light reversed. (If on, the light is turned off; if off, the light is turned on.) Buttons in the corners change the state of 3 buttons; buttons on an edge change the state of 4 buttons and other buttons change the state of 5. For example, if the buttons marked X on the left below were to be pressed, the display would change to the image on the right.
The aim of the game is, starting from any initial set of lights on in the display, to press buttons to get the display to a state where all lights are off. When adjacent buttons are pressed, the action of one button can undo the effect of another. For instance, in the display below, pressing buttons marked X in the left display results in the right display.
Note that the buttons in row 2 column 3 and row 2 column 5 both change the state of the button in row 2 column 4, so that, in the end, its state is unchanged.
Write a program to solve the puzzle.
The first line of the input is a positive integer n which is the number of
puzzles that follow. Each puzzle will be five lines, each of which has six 0's
or 1's separated by one or more spaces. A 0 indicates that the light is off,
while a 1 indicates that the light is on initially.
For each puzzle, the output consists of a line with the string: "PUZZLE
#m", where m is the index of the puzzle in the input file. Following that
line, is a puzzle-like display (in the same format as the input) . In this case,
1's indicate buttons that must be pressed to solve the puzzle, while 0's indicate
buttons, which are not pressed. There should be exactly one space between each
0 or 1 in the output puzzle-like display.
Source: Greater New York 2002