算法练习的简单题型，大家来一起呗

用循环求余得到每一位数字，统计3的个数

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int k = in.nextInt();
        while(true) {
            int t = n;
            int c3 = 0;
            while(t>0) {
                if(t%10 == 3)
                    c3++;
                t = t/10;
            }
            if(c3>=k)
                break;
            n++;
        }
        System.out.println(n);
    }
}