[알고리즘] 124나라의 숫자

#include<iostream>
#include<vector>
#include<cmath>
#include<algorithm>
using namespace std;
 
/*

8 / 3 = 2 ... 2
2 / 3 = 0 ... 2

9 / 3 = 3 ... 0
3 / 3 = 1 ... 0

10 /3  = 3 ... 1
3  / 3 = 1 ... 0 2 1


11 / 3=  3 ... 2
2  / 3 = 0 ... 2


3* 3  + 1* 3

12 / 3 =3 .. 0 3
3  / 3 =1 .. 0 3

13 / 3 = 4 ... 1
4 / 3  = 1 ... 1
1 / 3  = 0 ... 1



*/
string change124(int no)
{
 
  int a,b;
  string answer;
  while(no != 0)
  {
          a = no /3;
        b = no %3;
    if(b == 0) 
    {
          a -=1;
          answer += '4';
    }else answer += '0' + b;
    no = a;
  }
  reverse(answer.begin(), answer.end());
  
    return answer;
}
 
int main()
{
    int testNo = 10;
    string testAnswer = change124(testNo);
 
    cout<<testAnswer;
}