package offer;

/**
 * @Package Name : ${PACKAG_NAME}
 * @Creation Date : 2018年12月27日上午7:19
 * @Function : todo
 */
public class calculate_1_count {

    public static void main(String[] args) {

        int n = 11;

        System.out.println(count(n));

    }


    static int count(int n) {
        if (n <= 0) {
            return 0;
        }
        int count = 0;
        for (int i = 1; i <= n; ++i) {
            count += time_n(i);
        }
        return count;
    }
    static int time_n(int n) {
        if (n < 10) {
            if (n == 1) {
                return 1;
            } else {
                return 0;
            }
        }

        int sum = 0;

        if (n % 10 == 1) {
            sum++;
        }
        sum += time_n(n / 10);

        return sum;

    }

}