[백준] 1748번 : 수 이어 쓰기1 - Java(자바)

https://www.acmicpc.net/problem/1748

import java.util.Scanner;
public class Main {
    static int zero(int n){
        int z=1;
        if(n<=0) z=0;
        else{
            for(int i=1;i<=n-1;i++){
                z*=10;
            }
        }
        return z;
    }
    public static void main(String args[]) {
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        String k=Integer.toString(n);
        int len=k.length();
        int count=10;
        int num=0;
        while(n>0){
             num+=(n-zero(len)+1)*len;
             n=zero(len)-1;
             len--;
             
        }
        System.out.print(num);
    }
}