Complete 124country_number(124나라의숫자)

bongf/java/src/level2/Country124Number.java

@@ -0,0 +1,21 @@
+package level2;
+
+public class Country124Number {
+    public static void main(String[] args) {
+        Country124Number country124Number = new Country124Number();
+        System.out.println(country124Number.solution(18)); //124
+    }
+
+    public String solution(int n) {
+        int[] nums = new int[]{1, 2, 4};
+        StringBuilder answer = new StringBuilder();
+
+        while(n>0) {
+            n -= 1;
+            answer = answer.insert(0, nums[(n%3)]);
+            n /= 3;
+        }
+
+        return answer.toString();
+    }
+}

bongf/python/level2/124country_number.py

@@ -0,0 +1,54 @@
+def solution(n):
+    nums = [1, 2, 4]
+    sum = 0 
+    ## 자리수 구하기 i 
+    for i in range(1, 19):
+        sum += 3**i
+        if(sum >= n):
+            break
+    ## 자리수 j 
+    j = i
+    ## 해당 자리 수의 몇 번째 수 k 
+    k = n - (sum - 3**i)
+
+    ans = ['4'] * j 
+
+
+    for i in range(j):
+        m, n = divmod(k, (3**(j-1-i)))
+        if n == 0 :
+            m -= 1
+            ans[i] = str(nums[m])
+            break
+        else : 
+            ans[i] = str(nums[m])
+            k = n 
+
+
+    answer = ''.join(ans)
+    return answer
+
+def solution2(n):
+    num = ['1','2','4']
+    answer = ''
+
+    while n > 0 :
+        n -= 1
+        answer = num[n%3] + answer 
+        n //= 3
+
+    return answer 
+
+
+print(solution(1))
+print(solution(2))
+print(solution(3))
+print(solution(4))
+print(solution(5))
+print(solution(6))
+print(solution(7))
+print(solution(8))
+print(solution(9))
+print(solution(18)) ##124
+
+