题解 | [NOIP2010]数字统计

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
         Scanner scan = new Scanner(System.in);
         int L = scan.nextInt();
         int R = scan.nextInt();
         int count = 0;
         for(int i=L;i<=R;i++){
            int tem = i;//防止改变i的值
            while(tem!=0){
                if(tem%10==2){
                    count++;
                }
                tem/=10;
            }
         }
         System.out.println(count);
    }
}