[백준] 5692번 : 팩토리얼 진법 - Dart(다트)

https://www.acmicpc.net/problem/5692

import 'dart:io';
void main(){
    for(;;){
        int a=int.parse(stdin.readLineSync()!);
        if(a==0) break;
        int count=1;
        int num=1;
        int sum=0;
        while(a>0){
            int n=a%10;
            sum+=n*num;
            a~/=10;
            num*=++count;
        }
        print(sum);
    }
}