题解 | 记数问题

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 in = new Scanner(System.in);
        int n = in.nextInt();
        int x = in.nextInt();

        int count = 0;
        for (int i = 1; i <= n; i++) {
            //将i转换为字符串，得到i的长度
            String str = String.valueOf(i); // 1 -> '1'
            for (int j = 1; j <= str.length(); j++) { //m=12345
                if ( Character.getNumericValue(str.charAt(j-1)) == x) {
                    count++;
                }
            }
        }
        System.out.println(count);
    }
}