多维数组的指针:
假设有一个char型数组 board[3][3]
*board→board[0] 等价于 &board[0][0]
**board→board[0][0]→*board[0]
**board+1=board[0][0]+1=*board[0]+1
*board+1=&board[0][1]=board[0]+1
*board[x]=board[x][0]=*(*board+3x)
多维数组的指针:
假设有一个char型数组 board[3][3]
*board→board[0] 等价于 &board[0][0]
**board→board[0][0]→*board[0]
**board+1=board[0][0]+1=*board[0]+1
*board+1=&board[0][1]=board[0]+1
*board[x]=board[x][0]=*(*board+3x)