2829: 数1的个数

解题思路:

注意事项:

参考代码:

public class Main {

    public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int count = 0;

        for (int i = 1; i <= n; i++) {

            int temp = i;

            while (temp != 0) {

                if (temp % 10 == 1) {//分离每个数字，看是否有1出现

                    count++;//如果有，则相加

                }

                temp /= 10;//累加

            }

        }

        System.out.println(count);

    }

}