时间复杂度O(Mn)

public void gameOfLife(int[][] board)
    {
        if(board.length == 0 || board[0].length==0) return;
        int m = board.length, n = board[0].length;

        int[] neighbor = {0, 1, -1};
        for(int i = 0; i < m; i++)
            for(int j = 0; j < n; j++)
                if(board[i][j] % 10 == 1)
                    for(int k = 0; k < 3; k++)
                        for(int l = 0; l < 3; l++)
                        {
                            int left = i + neighbor[k];
                            int right = j + neighbor[l];
                            if(neighbor[k] == 0 && neighbor[l] == 0)
                                continue;
                            if(left >= 0 && right >= 0 && left < m && right < n)
                                board[left][right] += 10;
                        }
        for(int i = 0; i < m; i++)
            for(int j = 0; j < n; j++)
                if(board[i][j] == 21 || board[i][j] == 31)
                    board[i][j] = 1;
                else if(board[i][j] == 30)
                    board[i][j] = 1;
                else
                    board[i][j] = 0;


    }

自己实现:时间复杂度O(n**2)

public static void gameOfLife(int[][] board) {
        int r=board.length;
        int c=board[0].length;
        /*if(c==0)
            return;*/
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                //别忘记前提条件在什么时候才会影响周围的数字
                if (board[i][j] %10==1 ) {//由于后面的数字被影响过了，所以判断个位是否为1
                    for (int m = -1; m < 2; m++) {
                        if(i+m<0||i+m>=r)
                            continue;
                        for (int n = -1; n < 2 ; n++) {
                            if(m==0&&n==0||j+n<0||j+n>=c)
                                continue;
                            board[i+m][j+n]+=10;
                        }
                    }
                    //注意在这里并不可获取到所有更新后的值
                    //System.out.print(board[i][j]+"\t");
                }
                }
        }
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                System.out.print(board[i][j]+"\t");
            }
            System.out.println();
        }
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                int value=board[i][j];
                if((value%10==1&&(value/10==2)) ||(value/10==3)){
                    board[i][j]=1;
                }
                else board[i][j]=0;
            }
        }

bug版本：