有n米的壹口井,青蛙每天向上爬3米掉下來1米,請問多少天後可以爬出來?用java編程做出來.

System.out.println("請輸入井的高度(米)：");

Scanner sc = new Scanner(System.in);

String line = sc.next();

int n = 0;

try{

n = Integer.valueOf(line);

}catch(NumberFormatException e){

System.out.println("輸入錯誤！");

}

int i = 0, m = 0;

while(m < n){

i++;

m += 3 - 1;

}

System.out.println("這只青蛙花了" + i + "天爬出來");

}