题解 | 记数问题

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int n = in.nextInt(),x = in.nextInt();
        int cnt = 0;
        for(int i=1;i<=n;i++){
            int j = i;
            while(true){
                if(j==0)break;
                if(j%10==x)cnt++;
                j/=10;
            }
        }
        System.out.println(cnt);
    }
}