Game of life in go

game-of-life.go

package main

import "fmt"

type Cell struct {
        x     int
        y     int
        state int
}

const (
        DEAD = iota
        ALIVE
)

func main() {
        board := make([][]int, 9)
        for i := range board {
                board[i] = make([]int, 9)
        }

        board[0][0] = 1
        board[0][1] = 1
        board[0][2] = 1
        board[1][0] = 1
        board[1][1] = 1
        board[1][2] = 1
        board[2][0] = 1
        board[2][1] = 1
        board[2][2] = 1

        iterations := 3

        fmt.Println("Initial board:")
        showBoard(board)

        for i := 0; i < iterations; i++ {
                calculateNextBoard(board)
        }
        fmt.Println("final board:")
        showBoard(board)

}

func calculateNextBoard(board [][]int) {
        var nextBoard [][]int
        nextBoard = make([][]int, len(board))
        for i := range board {
                nextBoard[i] = make([]int, len(board[i]))
        }

        for i := range board {
                for j := range board[i] {
                        cell := Cell{i, j, board[i][j]}
                        aliveNeighbours := getAliveNeighbours(cell, board)
                        nextBoard[i][j] = calculateNextState(cell, aliveNeighbours)
                }
        }

        for i := range board {
                for j := range board[i] {
                        board[i][j] = nextBoard[i][j]
                }
        }
}

func calculateNextState(cell Cell, aliveNeighbours int) int {
        switch cell.state {
        case ALIVE:
                if aliveNeighbours >= 2 && aliveNeighbours <= 3 {
                        return ALIVE
                }
        case DEAD:
                if aliveNeighbours == 3 {
                        return ALIVE
                }
        }
        return DEAD
}

func getAliveNeighbours(cell Cell, board [][]int) int {
        aliveNeighbours := 0
        for i := cell.x - 1; i <= cell.x+1; i++ {
                for j := cell.y - 1; j <= cell.y+1; j++ {
                        if i == cell.x && j == cell.y {
                                continue
                        }
                        if i >= 0 && i < len(board) && j >= 0 && j < len(board[i]) && board[i][j] == ALIVE {
                                aliveNeighbours++
                        }
                }
        }

        // fmt.Printf("Alive neighbours for cell (%d, %d): %d \n", cell.x, cell.y, aliveNeighbours)
        return aliveNeighbours
}

func showBoard(board [][]int) {
        for i := range board {
                for j := range board[i] {
                        fmt.Printf("%d ", board[i][j])
                }
                fmt.Println()
        }
}