19.计数问题

题目

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		int n = sc.nextInt();
		int res = 0;
		int x = sc.nextInt();
		for(int i=1;i<=n;i++) {
			String s = i + "";
			for(int j=0;j<s.length();j++) {
				int c = s.charAt(j) - '0';
				if(c == x)
					res++;
			}
		}
		System.out.println(res);
	}
}