Game of Life Simulation Rules:
Each grid location is either empty or occupied by a single living cell (X). A location's neighbors are any cells in the surrounding eight adjacent locations, In the example below, the shaded location has three neighbors containing living cells.
The Game of life world is toroidal, this means that it wraps around in both dimensions., In other words, the top-most and bottom-most rows are considered to neighbor each other, as do the left-most and right-most columns. For example, the top-right X square in the example above has two neighbors that contain living cells: the cell down /left from it, and the cell up/right from it (which is the grid's bottom-left cell. To make sure that the definition of "neighbor" is well-defined, you may assume that the board's dimensions are at least 3x3.
The simulation starts with an initial pattern of cells on the grid and computes successive generations of cells according to the following rules:
- A location that has zero or one neighbors will be empty in the next generation. If a cell was there, it dies.
- A location with two neighbors is stable. If it had a cell, it still contains a cell. If it was empty, it's still empty.
- A location with three neighbors will contain a cell in the next generation. If it was unoccupied before, a new cell is born. If it currently contains a cell, the cell remains.
- A location with four or more neighbors will be empty in the next generation. If there was a cell in that location, it dies of overcrowding.
The births and deaths that transform one generation to the next all take effect simultaneously. When you are computing a new generation, new births/deaths in that generation don't impact other cells in that generation. Any changes (births or deaths) in a given generation k start to have effect on other neighboring cells in generation k + 1.
Check your understanding of the game rules by looking at the following example below, The two patterns at right should alternate forever.
Here is another example, The pattern below does not change on each iteration, because each cell has exactly three living neighbors. This is called a "stable" pattern or a "still life".
Input Files:
The grid of bacteria in your program gets it initial state from one of a set of provided input text flies, which follow a particular format. When your program reads the grid file, you should re-prompt the user if the file specified does not exist. If it does exist, you may assume that all of its contents are valid and follow the proper format. You do not need to write any code to handle a misformatted file. The behavior of your program in such a case is not defined in this spec, it can crash, it can terminate, etc. Note that the input file name might contain spaces.
In each input file, the first two lines will contain integers rand c representing the number of rows and columns in the grid, respectively. The next lines of the file will contain the grid itself, a set of characters of size rx c with a line break (\n) after each row Each grid character will be either a ‘-’ (minus sign) for an empty dead cell, or an ‘X’ (uppercase X) for a living cell. The input file might contain additional lines of information after the grid lines, such as comments by its author or even junk/garbage data; any such content should be ignored by your program. You may assume that the world's size is at least 3x3.
The input files will exist in the same working directory as your program. For example, the following text might be the contents of a file simple.txt, a 5x9 grid with 3 initially live cells:
